diff --git a/.github/container/ejabberdctl.template b/.github/container/ejabberdctl.template
index 1a8df3e12..9afc96a81 100755
--- a/.github/container/ejabberdctl.template
+++ b/.github/container/ejabberdctl.template
@@ -187,8 +187,8 @@ livewarning()
         echo "Please be extremely cautious with your actions,"
         echo "and exit immediately if you are not completely sure."
         echo ""
-        echo "To exit this LIVE mode and stop ejabberd, press:"
-        echo "  q().  and press the Enter key"
+        echo "To exit and detach this shell from ejabberd, press:"
+        echo "  control+g and then q"
         echo ""
         echo "--------------------------------------------------------------------"
         echo "To bypass permanently this warning, add to ejabberdctl.cfg the line:"
diff --git a/.github/workflows/runtime.yml b/.github/workflows/runtime.yml
index 4b62858f8..714edd269 100644
--- a/.github/workflows/runtime.yml
+++ b/.github/workflows/runtime.yml
@@ -33,9 +33,6 @@ jobs:
       matrix:
         otp: ['20.3', '25.3', '26']
         rebar: ['rebar', 'rebar3']
-        exclude:
-        - otp: '26'
-          rebar: 'rebar'
     runs-on: ubuntu-latest
     container:
       image: erlang:${{ matrix.otp }}
@@ -44,6 +41,16 @@ jobs:
 
     - uses: actions/checkout@v4
 
+    - name: Get compatible Rebar binaries
+      if: matrix.otp < 23
+      run: |
+        rm rebar
+        rm rebar3
+        wget https://github.com/processone/ejabberd/raw/21.12/rebar
+        wget https://github.com/processone/ejabberd/raw/21.12/rebar3
+        chmod +x rebar
+        chmod +x rebar3
+
     - name: Prepare libraries
       run: |
         apt-get -qq update
@@ -54,78 +61,224 @@ jobs:
     - name: Compile
       run: |
         ./autogen.sh
-        ./configure --with-rebar=`which ${{ matrix.rebar }}` \
+        ./configure --with-rebar=${{ matrix.rebar }} \
                     --prefix=/tmp/ejabberd \
                     --enable-all \
                     --disable-elixir \
+                    --disable-tools \
                     --disable-odbc
         make update
         make
 
     - run: make xref
 
-    - name: Test rel (rebar2)
+    - name: Prepare rel (rebar2)
       if: matrix.rebar == 'rebar'
       run: |
-        make rel
-        rel/ejabberd/bin/ejabberdctl start \
-          && rel/ejabberd/bin/ejabberdctl started
-        rel/ejabberd/bin/ejabberdctl register user1 localhost s0mePass
-        rel/ejabberd/bin/ejabberdctl registered_users localhost
-        cat rel/ejabberd/logs/*
+        mkdir -p _build/prod && ln -s `pwd`/rel/ _build/prod/rel
+        mkdir -p _build/dev  && ln -s `pwd`/rel/ _build/dev/rel
 
-    - name: Test rel
-      if: matrix.rebar != 'rebar'
+    - name: Run rel
       run: |
         make rel
         _build/prod/rel/ejabberd/bin/ejabberdctl start \
           && _build/prod/rel/ejabberd/bin/ejabberdctl started
         _build/prod/rel/ejabberd/bin/ejabberdctl register user1 localhost s0mePass
-        _build/prod/rel/ejabberd/bin/ejabberdctl registered_users localhost
+        _build/prod/rel/ejabberd/bin/ejabberdctl registered_users localhost > registered.log
         _build/prod/rel/ejabberd/bin/ejabberdctl stop \
           && _build/prod/rel/ejabberd/bin/ejabberdctl stopped
-        cat _build/prod/rel/ejabberd/logs/*
 
-    - name: Test dev
-      if: matrix.rebar != 'rebar'
+    - name: Run dev
       run: |
         make dev
         _build/dev/rel/ejabberd/bin/ejabberdctl start \
           && _build/dev/rel/ejabberd/bin/ejabberdctl started
-        _build/dev/rel/ejabberd/bin/ejabberdctl register user1 localhost s0mePass
-        _build/dev/rel/ejabberd/bin/ejabberdctl registered_users localhost
+        _build/dev/rel/ejabberd/bin/ejabberdctl register user2 localhost s0mePass
+        _build/dev/rel/ejabberd/bin/ejabberdctl registered_users localhost >> registered.log
         _build/dev/rel/ejabberd/bin/ejabberdctl stop \
           && _build/dev/rel/ejabberd/bin/ejabberdctl stopped
+
+    - name: Run install
+      run: |
+        make install
+        /tmp/ejabberd/sbin/ejabberdctl start \
+          && /tmp/ejabberd/sbin/ejabberdctl started
+        /tmp/ejabberd/sbin/ejabberdctl register user3 localhost s0mePass
+        /tmp/ejabberd/sbin/ejabberdctl registered_users localhost >> registered.log
+        /tmp/ejabberd/sbin/ejabberdctl stop \
+          && /tmp/ejabberd/sbin/ejabberdctl stopped
+
+    - name: View logs
+      run: |
+        echo "===> Registered:"
+        cat registered.log
+        echo "===> Prod:"
+        cat _build/prod/rel/ejabberd/logs/*
+        echo "===> Dev:"
         cat _build/dev/rel/ejabberd/logs/*
+        echo "===> Install:"
+        cat /tmp/ejabberd/var/log/ejabberd/*
+
+    - name: Check logs
+      run: |
+        grep -q '^user1$' registered.log
+        grep -q '^user2$' registered.log
+        grep -q '^user3$' registered.log
+        grep -q 'is started' _build/prod/rel/ejabberd/logs/ejabberd.log
+        grep -q 'is stopped' _build/prod/rel/ejabberd/logs/ejabberd.log
+        test $(find _build/prod/rel/ -empty -name error.log)
+        grep -q 'is started' _build/dev/rel/ejabberd/logs/ejabberd.log
+        grep -q 'is stopped' _build/dev/rel/ejabberd/logs/ejabberd.log
+        test $(find _build/dev/rel/ -empty -name error.log)
+        grep -q 'is started' /tmp/ejabberd/var/log/ejabberd/ejabberd.log
+        grep -q 'is stopped' /tmp/ejabberd/var/log/ejabberd/ejabberd.log
+        test $(find /tmp/ejabberd/var/log/ejabberd/ -empty -name error.log)
+
+    - name: View logs failures
+      if: always()
+      run: |
+        cat _build/prod/rel/ejabberd/logs/ejabberd.log
+        cat _build/prod/rel/ejabberd/logs/error.log
+        cat _build/dev/rel/ejabberd/logs/ejabberd.log
+        cat _build/dev/rel/ejabberd/logs/error.log
+        cat /tmp/ejabberd/var/log/ejabberd/ejabberd.log
+        cat /tmp/ejabberd/var/log/ejabberd/error.log
+
+  rebar3-elixir:
+    name: Rebar3+Elixir
+    strategy:
+      fail-fast: false
+      matrix:
+        otp: ['23.0', '25.3', '26']
+        elixir: ['1.13.4', '1.15.7', '1.16']
+        exclude:
+        - otp: '23.0'
+          elixir: '1.15.7'
+        - otp: '23.0'
+          elixir: '1.16'
+        - otp: '26'
+          elixir: '1.13.4'
+    runs-on: ubuntu-20.04
+
+    steps:
+
+    - uses: actions/checkout@v4
+
+    - name: Get specific Erlang/OTP
+      uses: erlef/setup-beam@v1
+      with:
+        otp-version: ${{matrix.otp}}
+        elixir-version: ${{matrix.elixir}}
+
+    - name: Prepare libraries
+      run: |
+        sudo apt-get -qq update
+        sudo apt-get -y purge libgd3 nginx
+        sudo apt-get -qq install libexpat1-dev libgd-dev libpam0g-dev \
+                                 libsqlite3-dev libwebp-dev libyaml-dev
+
+    - name: Enable ModPresenceDemo and an Elixir dependency
+      run: |
+        sed -i "s|^modules:|modules:\n  'ModPresenceDemo': {}|g" ejabberd.yml.example
+        cat ejabberd.yml.example
+        sed -i 's|^{deps, \(.*\)|{deps, \1\n  {decimal, ".*", {git, "https://github.com/ericmj/decimal", {branch, "main"}}}, |g' rebar.config
+        cat rebar.config
+
+    - name: Compile
+      run: |
+        ./autogen.sh
+        ./configure --with-rebar=rebar3 \
+                    --prefix=/tmp/ejabberd \
+                    --enable-all \
+                    --disable-odbc
+        make update
+        make
+
+    - run: make xref
+
+    - name: Run rel
+      run: |
+        make rel
+        _build/prod/rel/ejabberd/bin/ejabberdctl start \
+          && _build/prod/rel/ejabberd/bin/ejabberdctl started
+        _build/prod/rel/ejabberd/bin/ejabberdctl register user1 localhost s0mePass
+        _build/prod/rel/ejabberd/bin/ejabberdctl registered_users localhost > registered.log
+        _build/prod/rel/ejabberd/bin/ejabberdctl stop \
+          && _build/prod/rel/ejabberd/bin/ejabberdctl stopped
+
+    - name: Run dev
+      run: |
+        make dev
+        _build/dev/rel/ejabberd/bin/ejabberdctl start \
+          && _build/dev/rel/ejabberd/bin/ejabberdctl started
+        _build/dev/rel/ejabberd/bin/ejabberdctl register user2 localhost s0mePass
+        _build/dev/rel/ejabberd/bin/ejabberdctl registered_users localhost >> registered.log
+        _build/dev/rel/ejabberd/bin/ejabberdctl stop \
+          && _build/dev/rel/ejabberd/bin/ejabberdctl stopped
+
+    - name: Run install
+      run: |
+        make install
+        /tmp/ejabberd/sbin/ejabberdctl start \
+          && /tmp/ejabberd/sbin/ejabberdctl started
+        /tmp/ejabberd/sbin/ejabberdctl register user3 localhost s0mePass
+        /tmp/ejabberd/sbin/ejabberdctl registered_users localhost >> registered.log
+        /tmp/ejabberd/sbin/ejabberdctl stop \
+          && /tmp/ejabberd/sbin/ejabberdctl stopped
+
+    - name: View logs
+      if: always()
+      run: |
+        echo "===> Registered:"
+        cat registered.log
+        echo "===> Prod:"
+        cat _build/prod/rel/ejabberd/logs/*
+        echo "===> Dev:"
+        cat _build/dev/rel/ejabberd/logs/*
+        echo "===> Install:"
+        cat /tmp/ejabberd/var/log/ejabberd/*
+
+    - name: Check logs
+      if: always()
+      run: |
+        grep -q '^user1$' registered.log
+        grep -q '^user2$' registered.log
+        grep -q '^user3$' registered.log
+        grep -q 'is started' _build/prod/rel/ejabberd/logs/ejabberd.log
+        grep -q 'is stopped' _build/prod/rel/ejabberd/logs/ejabberd.log
+        grep -q 'module Presence Demo' _build/prod/rel/ejabberd/logs/ejabberd.log
+        test $(find _build/prod/ -empty -name error.log)
+        grep -q 'is started' _build/dev/rel/ejabberd/logs/ejabberd.log
+        grep -q 'is stopped' _build/dev/rel/ejabberd/logs/ejabberd.log
+        grep -q 'module Presence Demo' _build/dev/rel/ejabberd/logs/ejabberd.log
+        test $(find _build/dev/ -empty -name error.log)
+        grep -q 'is started' /tmp/ejabberd/var/log/ejabberd/ejabberd.log
+        grep -q 'is stopped' /tmp/ejabberd/var/log/ejabberd/ejabberd.log
+        grep -q 'module Presence Demo' /tmp/ejabberd/var/log/ejabberd/ejabberd.log
+        test $(find /tmp/ejabberd/var/log/ejabberd/ -empty -name error.log)
+
+    - name: View logs failures
+      if: failure()
+      run: |
+        cat _build/prod/rel/ejabberd/logs/ejabberd.log
+        cat _build/prod/rel/ejabberd/logs/error.log
+        cat _build/dev/rel/ejabberd/logs/ejabberd.log
+        cat _build/dev/rel/ejabberd/logs/error.log
+        cat /tmp/ejabberd/var/log/ejabberd/ejabberd.log
+        cat /tmp/ejabberd/var/log/ejabberd/error.log
 
   mix:
     name: Mix
     strategy:
       fail-fast: false
       matrix:
-        otp: ['21.3', '25.0', '26']
-        elixir: ['1.10.3', '1.11.4', '1.12.3', '1.13.4', '1.14.5', '1.15']
+        otp: ['23.0', '25.3', '26']
+        elixir: ['1.13.4', '1.15.7', '1.16']
         exclude:
-        - otp: '21.3'
-          elixir: '1.12.3'
-        - otp: '21.3'
-          elixir: '1.13.4'
-        - otp: '21.3'
-          elixir: '1.14.5'
-        - otp: '21.3'
-          elixir: '1.15'
-        - otp: '25.0'
-          elixir: '1.10.3'
-        - otp: '25.0'
-          elixir: '1.11.4'
-        - otp: '25.0'
-          elixir: '1.12.3'
-        - otp: '26'
-          elixir: '1.10.3'
-        - otp: '26'
-          elixir: '1.11.4'
-        - otp: '26'
-          elixir: '1.12.3'
+        - otp: '23.0'
+          elixir: '1.15.7'
+        - otp: '23.0'
+          elixir: '1.16'
         - otp: '26'
           elixir: '1.13.4'
     runs-on: ubuntu-20.04
@@ -155,13 +308,19 @@ jobs:
         echo "::remove-matcher owner=elixir-mixTestFailure::"
         echo "::remove-matcher owner=elixir-dialyzerOutputDefault::"
 
+    - name: Enable ModPresenceDemo and an Elixir dependency
+      run: |
+        sed -i "s|^modules:|modules:\n  'ModPresenceDemo': {}|g" ejabberd.yml.example
+        cat ejabberd.yml.example
+        sed -i 's|^{deps, \(.*\)|{deps, \1\n  {decimal, ".*", {git, "https://github.com/ericmj/decimal", {branch, "main"}}}, |g' rebar.config
+        cat rebar.config
+
     - name: Compile
       run: |
         ./autogen.sh
         ./configure --with-rebar=mix \
                     --prefix=/tmp/ejabberd \
                     --enable-all \
-                    --disable-elixir \
                     --disable-odbc
         mix deps.get
         make
@@ -188,17 +347,46 @@ jobs:
         _build/dev/rel/ejabberd/bin/ejabberdctl stop \
           && _build/dev/rel/ejabberd/bin/ejabberdctl stopped
 
-    - name: Check rel
+    - name: Run install
+      run: |
+        make install
+        /tmp/ejabberd/sbin/ejabberdctl start \
+          && /tmp/ejabberd/sbin/ejabberdctl started
+        /tmp/ejabberd/sbin/ejabberdctl register user3 localhost s0mePass
+        /tmp/ejabberd/sbin/ejabberdctl registered_users localhost >> registered.log
+        /tmp/ejabberd/sbin/ejabberdctl stop \
+          && /tmp/ejabberd/sbin/ejabberdctl stopped
+
+    - name: View logs
+      if: always()
+      run: |
+        echo "===> Registered:"
+        cat registered.log
+        echo "===> Prod:"
+        cat _build/prod/rel/ejabberd/logs/*
+        echo "===> Dev:"
+        cat _build/dev/rel/ejabberd/logs/*
+        echo "===> Install:"
+        cat /tmp/ejabberd/var/log/ejabberd/*
+
+    - name: Check logs
       if: always()
       run: |
         grep -q '^user1$' registered.log
         grep -q '^user2$' registered.log
+        grep -q '^user3$' registered.log
         grep -q 'is started' _build/prod/rel/ejabberd/logs/ejabberd.log
         grep -q 'is stopped' _build/prod/rel/ejabberd/logs/ejabberd.log
+        grep -q 'module Presence Demo' _build/prod/rel/ejabberd/logs/ejabberd.log
         test $(find _build/prod/ -empty -name error.log)
         grep -q 'is started' _build/dev/rel/ejabberd/logs/ejabberd.log
         grep -q 'is stopped' _build/dev/rel/ejabberd/logs/ejabberd.log
+        grep -q 'module Presence Demo' _build/dev/rel/ejabberd/logs/ejabberd.log
         test $(find _build/dev/ -empty -name error.log)
+        grep -q 'is started' /tmp/ejabberd/var/log/ejabberd/ejabberd.log
+        grep -q 'is stopped' /tmp/ejabberd/var/log/ejabberd/ejabberd.log
+        grep -q 'module Presence Demo' /tmp/ejabberd/var/log/ejabberd/ejabberd.log
+        test $(find /tmp/ejabberd/var/log/ejabberd/ -empty -name error.log)
 
     - name: View logs failures
       if: failure()
@@ -207,3 +395,5 @@ jobs:
         cat _build/prod/rel/ejabberd/logs/error.log
         cat _build/dev/rel/ejabberd/logs/ejabberd.log
         cat _build/dev/rel/ejabberd/logs/error.log
+        cat /tmp/ejabberd/var/log/ejabberd/ejabberd.log
+        cat /tmp/ejabberd/var/log/ejabberd/error.log
diff --git a/COMPILE.md b/COMPILE.md
index c6b10800a..80e932d65 100644
--- a/COMPILE.md
+++ b/COMPILE.md
@@ -28,7 +28,8 @@ Other optional libraries are:
 - PAM library, for Pluggable Authentication Modules (PAM)
 - ImageMagick's Convert program and Ghostscript fonts, for CAPTCHA
   challenges
-- Elixir ≥ 1.10.3, to support Elixir, and alternative to rebar/rebar3
+- Elixir ≥ 1.10.3, for Elixir support. It is recommended Elixir 1.13.4 or higher
+  and Erlang/OTP 23.0 or higher.
 
 If your system splits packages in libraries and development headers,
 install the development packages too.
@@ -89,7 +90,7 @@ Build an OTP Release
 Instead of installing ejabberd in the system, you can build an OTP release
 that includes all necessary to run ejabberd in a subdirectory:
 
-    ./configure --with-rebar=rebar3
+    ./configure
     make rel
 
 Or, if you have Elixir available and plan to develop Elixir code:
diff --git a/Makefile.in b/Makefile.in
index c56070eec..c287cbbd9 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -1,6 +1,12 @@
+#.
+#' definitions
+#
+
 REBAR = @ESCRIPT@ @rebar@
 MIX = @rebar@
+AWK = @AWK@
 INSTALL = @INSTALL@
+MKDIR_P = @MKDIR_P@
 SED = @SED@
 ERL = @ERL@
 
@@ -71,6 +77,10 @@ SPOOLDIR = @localstatedir@/lib/ejabberd
 # /var/log/ejabberd/
 LOGDIR = @localstatedir@/log/ejabberd
 
+#.
+#' install user
+#
+
 INSTALLUSER=@INSTALLUSER@
 # if no user was enabled, don't set privileges or ownership
 ifeq ($(INSTALLUSER),)
@@ -92,14 +102,20 @@ ifneq ($(INSTALLGROUP),)
   G_USER=-g $(INSTALLGROUP)
 endif
 
-ifeq "$(MIX)" "mix"
+#.
+#' rebar / rebar3 / mix
+#
+
+ifeq "$(notdir $(MIX))" "mix"
 REBAR_VER:=6
 REBAR_VER_318:=0
 else
-REBAR_VER:=$(shell $(REBAR) --version | awk -F '[ .]' '/rebar / {print $$2}')
-REBAR_VER_318:=$(shell $(REBAR) --version | awk -F '[ .]' '/rebar / {print ($$2 == 3 && $$3 >= 18 ? 1 : 0)}')
+REBAR_VER:=$(shell $(REBAR) --version | $(AWK) -F '[ .]' '/rebar / {print $$2}')
+REBAR_VER_318:=$(shell $(REBAR) --version | $(AWK) -F '[ .]' '/rebar / {print ($$2 == 3 && $$3 >= 18 ? 1 : 0)}')
 endif
 
+REBAR_ENABLE_ELIXIR = @elixir@
+
 ifeq "$(REBAR_VER)" "6"
   REBAR=$(MIX)
   SKIPDEPS=
@@ -113,10 +129,20 @@ ifeq "$(REBAR_VER)" "6"
   EBINDIR=$(DEPSDIR)/ejabberd/ebin
   XREFOPTIONS=graph
   CLEANARG=--deps
+  ELIXIR_LIBDIR_RAW=$(shell elixir -e "IO.puts(:filename.dirname(:code.lib_dir(:elixir)))" -e ":erlang.halt")
+  ELIXIR_LIBDIR=":$(ELIXIR_LIBDIR_RAW)"
   REBARREL=MIX_ENV=prod $(REBAR) release --overwrite
   REBARDEV=MIX_ENV=dev $(REBAR) release --overwrite
   RELIVECMD=escript rel/relive.escript && MIX_ENV=dev RELIVE=true iex --name ejabberd@localhost -S mix run
+  REL_LIB_DIR = _build/dev/rel/ejabberd/lib
+  COPY_REL_TARGET = dev
 else
+ifeq ($(REBAR_ENABLE_ELIXIR),true)
+  ELIXIR_LIBDIR_RAW=$(shell elixir -e "IO.puts(:filename.dirname(:code.lib_dir(:elixir)))" -e ":erlang.halt")
+  ELIXIR_LIBDIR=":$(ELIXIR_LIBDIR_RAW)"
+  EXPLICIT_ELIXIR_COMPILE=MIX_ENV=default mix compile.elixir
+  PREPARE_ELIXIR_SCRIPTS=$(MKDIR_P) rel/overlays; cp $(ELIXIR_LIBDIR_RAW)/../bin/iex rel/overlays/; cp $(ELIXIR_LIBDIR_RAW)/../bin/elixir rel/overlays/; sed -i 's|ERTS_BIN=$$|ERTS_BIN=$$SCRIPT_PATH/../../erts-{{erts_vsn}}/bin/|' rel/overlays/elixir
+endif
 ifeq "$(REBAR_VER)" "3"
   SKIPDEPS=
   LISTDEPS=tree
@@ -136,6 +162,8 @@ endif
   REBARREL=$(REBAR) as prod tar
   REBARDEV=REBAR_PROFILE=dev $(REBAR) release
   RELIVECMD=$(REBAR) relive
+  REL_LIB_DIR = _build/dev/rel/ejabberd/lib
+  COPY_REL_TARGET = dev
 else
   SKIPDEPS=skip_deps=true
   LISTDEPS=-q list-deps
@@ -152,9 +180,15 @@ else
   REBARDEV=
   RELIVECMD=@echo "Rebar2 detected... relive not supported.\
 	 \nTry: ./configure --with-rebar=./rebar3 ; make relive"
+  REL_LIB_DIR = rel/ejabberd/lib
+  COPY_REL_TARGET = rel
 endif
 endif
 
+#.
+#' main targets
+#
+
 all: scripts deps src
 
 deps: $(DEPSDIR)/.got
@@ -162,7 +196,7 @@ deps: $(DEPSDIR)/.got
 $(DEPSDIR)/.got:
 	rm -rf $(DEPSDIR)/.got
 	rm -rf $(DEPSDIR)/.built
-	mkdir -p $(DEPSDIR)
+	$(MKDIR_P) $(DEPSDIR)
 	$(REBAR) $(GET_DEPS) && :> $(DEPSDIR)/.got
 	$(CONFIGURE_DEPS)
 
@@ -171,6 +205,7 @@ $(DEPSDIR)/.built: $(DEPSDIR)/.got
 
 src: $(DEPSDIR)/.built
 	$(REBAR) $(SKIPDEPS) compile
+	$(EXPLICIT_ELIXIR_COMPILE)
 
 update:
 	rm -rf $(DEPSDIR)/.got
@@ -197,6 +232,10 @@ edoc:
 	$(ERL) -noinput +B -eval \
         'case edoc:application(ejabberd, ".", []) of ok -> halt(0); error -> halt(1) end.'
 
+#.
+#' copy-files
+#
+
 JOIN_PATHS=$(if $(wordlist 2,1000,$(1)),$(firstword $(1))/$(call JOIN_PATHS,$(wordlist 2,1000,$(1))),$(1))
 
 VERSIONED_DEP=$(if $(DEP_$(1)_VERSION),$(DEP_$(1)_VERSION),$(1))
@@ -282,24 +321,54 @@ copy-files:
 
 copy-files-sub: copy-files-sub2
 
+#.
+#' copy-files-rel
+#
+
+copy-files-rel: $(COPY_REL_TARGET)
+	#
+	# Libraries
+	(cd $(REL_LIB_DIR) && find . -follow -type f ! -executable -exec $(INSTALL) -vDm 640 $(G_USER) {} $(DESTDIR)$(LIBDIR)/{} \;)
+	#
+	# *.so:
+	(cd $(REL_LIB_DIR) && find . -follow -type f -executable -name *.so -exec $(INSTALL) -vDm 640 $(G_USER) {} $(DESTDIR)$(LIBDIR)/{} \;)
+	#
+	# Executable files
+	(cd $(REL_LIB_DIR) && find . -follow -type f -executable ! -name *.so -exec $(INSTALL) -vDm 550 $(G_USER) {} $(DESTDIR)$(LIBDIR)/{} \;)
+
+#.
+#' uninstall-librel
+#
+
+uninstall-librel:
+	(cd $(REL_LIB_DIR) && find . -follow -type f -exec rm -fv -v $(DESTDIR)$(LIBDIR)/{} \;)
+	(cd $(REL_LIB_DIR) && find . -follow -depth -type d -exec rm -dv -v $(DESTDIR)$(LIBDIR)/{} \;)
+
+#.
+#' relive
+#
+
 relive:
 	$(RELIVECMD)
 
 relivelibdir=$(shell pwd)/$(DEPSDIR)
 relivedir=$(shell pwd)/_build/relive
-iexpath=$(shell which iex)
 CONFIG_DIR = ${relivedir}/conf
 SPOOL_DIR = ${relivedir}/database
 LOGS_DIR = ${relivedir}/logs
 
+#.
+#' scripts
+#
+
 ejabberdctl.relive:
 	$(SED)  -e "s*{{installuser}}*@INSTALLUSER@*g" \
 		-e "s*{{config_dir}}*${CONFIG_DIR}*g" \
 		-e "s*{{logs_dir}}*${LOGS_DIR}*g" \
 		-e "s*{{spool_dir}}*${SPOOL_DIR}*g" \
-		-e "s*{{bindir}}/iex*$(iexpath)*g" \
 		-e "s*{{bindir}}*@bindir@*g" \
-		-e "s*{{libdir}}*${relivelibdir}*g" \
+		-e "s*{{libdir}}*${relivelibdir}${ELIXIR_LIBDIR}*g" \
+		-e "s*{{iexpath}}*@IEX@*g" \
 		-e "s*{{erl}}*@ERL@*g" \
 		-e "s*{{epmd}}*@EPMD@*g" ejabberdctl.template \
 		> ejabberdctl.relive
@@ -322,14 +391,23 @@ ejabberdctl.example: vars.config
 		-e "s*{{logs_dir}}*${LOGDIR}*g" \
 		-e "s*{{spool_dir}}*${SPOOLDIR}*g" \
 		-e "s*{{bindir}}*@bindir@*g" \
-		-e "s*{{libdir}}*@libdir@*g" \
+		-e "s*{{libdir}}*@libdir@${ELIXIR_LIBDIR}*g" \
+		-e "s*{{iexpath}}*@IEX@*g" \
 		-e "s*{{erl}}*@ERL@*g" \
 		-e "s*{{epmd}}*@EPMD@*g" ejabberdctl.template \
 		> ejabberdctl.example
 
 scripts: ejabberd.init ejabberd.service ejabberdctl.example
 
-install: copy-files
+#.
+#' install
+#
+
+install: copy-files install-main
+
+install-rel: copy-files-rel install-main
+
+install-main:
 	#
 	# Configuration files
 	$(INSTALL) -d -m 750 $(G_USER) $(DESTDIR)$(ETCDIR)
@@ -368,8 +446,14 @@ install: copy-files
 		|| echo "Man page not included in sources"
 	$(INSTALL) -m 644 COPYING $(DESTDIR)$(DOCDIR)
 
+#.
+#' uninstall
+#
+
 uninstall: uninstall-binary
 
+uninstall-rel: uninstall-binary uninstall-librel
+
 uninstall-binary:
 	rm -f  $(DESTDIR)$(SBINDIR)/ejabberdctl
 	rm -f  $(DESTDIR)$(BINDIR)/iex
@@ -398,6 +482,7 @@ uninstall-binary:
 	rm -fr $(DESTDIR)$(LUADIR)
 	rm -fr $(DESTDIR)$(PRIVDIR)
 	rm -fr $(DESTDIR)$(EJABBERDDIR)
+	rm -f  $(DESTDIR)$(MANDIR)/ejabberd.yml.5
 
 uninstall-all: uninstall-binary
 	rm -rf $(DESTDIR)$(ETCDIR)
@@ -405,6 +490,10 @@ uninstall-all: uninstall-binary
 	rm -rf $(DESTDIR)$(SPOOLDIR)
 	rm -rf $(DESTDIR)$(LOGDIR)
 
+#.
+#' clean
+#
+
 clean:
 	rm -rf $(DEPSDIR)/.got
 	rm -rf $(DEPSDIR)/.built
@@ -427,19 +516,39 @@ distclean: clean clean-rel
 	rm -f Makefile
 	rm -f vars.config
 
-rel:
+#.
+#' releases
+#
+
+rel: prod
+
+prod:
+	$(PREPARE_ELIXIR_SCRIPTS)
 	$(REBARREL)
 
 DEV_CONFIG = _build/dev/rel/ejabberd/conf/ejabberd.yml
 
 dev $(DEV_CONFIG):
+	$(PREPARE_ELIXIR_SCRIPTS)
 	$(REBARDEV)
 
+#.
+#' tags
+#
+
 TAGS:
-	etags *.erl
+	etags src/*.erl
+
+#.
+#' makefile
+#
 
 Makefile: Makefile.in
 
+#.
+#' dialyzer
+#
+
 ifeq "$(REBAR_VER)" "3"
 dialyzer:
 	find src/*_opt.erl -type f \! -regex ".*git.*" -exec sed -i 's/re:mp/  tuple/g' {} \;
@@ -449,7 +558,7 @@ else
 deps := $(wildcard $(DEPSDIR)/*/ebin)
 
 dialyzer/erlang.plt:
-	@mkdir -p dialyzer
+	@$(MKDIR_P) dialyzer
 	@dialyzer --build_plt --output_plt dialyzer/erlang.plt \
 	-o dialyzer/erlang.log --apps kernel stdlib sasl crypto \
 	public_key ssl mnesia inets odbc compiler erts \
@@ -457,13 +566,13 @@ dialyzer/erlang.plt:
 	status=$$? ; if [ $$status -ne 2 ]; then exit $$status; else exit 0; fi
 
 dialyzer/deps.plt:
-	@mkdir -p dialyzer
+	@$(MKDIR_P) dialyzer
 	@dialyzer --build_plt --output_plt dialyzer/deps.plt \
 	-o dialyzer/deps.log $(deps); \
 	status=$$? ; if [ $$status -ne 2 ]; then exit $$status; else exit 0; fi
 
 dialyzer/ejabberd.plt:
-	@mkdir -p dialyzer
+	@$(MKDIR_P) dialyzer
 	@dialyzer --build_plt --output_plt dialyzer/ejabberd.plt \
 	-o dialyzer/ejabberd.log ebin; \
 	status=$$? ; if [ $$status -ne 2 ]; then exit $$status; else exit 0; fi
@@ -486,6 +595,10 @@ dialyzer: erlang_plt deps_plt ejabberd_plt
 	status=$$? ; if [ $$status -ne 2 ]; then exit $$status; else exit 0; fi
 endif
 
+#.
+#' test
+#
+
 test:
 	@echo "************************** NOTICE ***************************************"
 	@cat test/README
@@ -493,9 +606,18 @@ test:
 	@cd priv && ln -sf ../sql
 	$(REBAR) $(SKIPDEPS) ct
 
-.PHONY: src edoc dialyzer Makefile TAGS clean clean-rel distclean rel \
+#.
+#' phony
+#
+
+.PHONY: src edoc dialyzer Makefile TAGS clean clean-rel distclean prod rel \
 	install uninstall uninstall-binary uninstall-all translations deps test \
-	quicktest erlang_plt deps_plt ejabberd_plt xref hooks options
+	all dev doap help install-rel relive scripts uninstall-rel update \
+	erlang_plt deps_plt ejabberd_plt xref hooks options
+
+#.
+#' help
+#
 
 help:
 	@echo ""
@@ -508,10 +630,12 @@ help:
 	@echo "  distclean      Clean completely the development files"
 	@echo ""
 	@echo "  install        Install ejabberd to /usr/local"
+	@echo "  install-rel    Install ejabberd to /usr/local (using release)"
 	@echo "  uninstall      Uninstall ejabberd (buggy)"
+	@echo "  uninstall-rel  Uninstall ejabberd (using release)"
 	@echo "  uninstall-all  Uninstall also configuration, logs, mnesia... (buggy)"
 	@echo ""
-	@echo "  rel            Build a production release"
+	@echo "  prod           Build a production release"
 	@echo "  dev            Build a development release"
 	@echo "  relive         Start a live ejabberd in _build/relive/"
 	@echo ""
@@ -519,9 +643,13 @@ help:
 	@echo "  edoc           Generate edoc documentation (unused)"
 	@echo "  options        Generate ejabberd_option.erl"
 	@echo "  translations   Extract translation files (requires --enable-tools)"
-	@echo "  tags           Generate tags file for text editors"
+	@echo "  TAGS           Generate tags file for text editors"
 	@echo ""
 	@echo "  dialyzer       Run Dialyzer static analyzer"
 	@echo "  hooks          Run hooks validator"
 	@echo "  test           Run Common Tests suite"
 	@echo "  xref           Run cross reference analysis"
+
+#.
+#'
+# vim: foldmarker=#',#. foldmethod=marker:
diff --git a/config/runtime.exs b/config/runtime.exs
index b4e6dc5f1..fb2372ea6 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -8,6 +8,6 @@ end
 rootpath = System.get_env("RELEASE_ROOT", rootdefault)
 config :ejabberd,
   file: Path.join(rootpath, "conf/ejabberd.yml"),
-  log_path: Path.join(rootpath, 'logs/ejabberd.log')
+  log_path: Path.join(rootpath, "logs/ejabberd.log")
 config :mnesia,
-  dir: Path.join(rootpath, 'database/')
+  dir: Path.join(rootpath, "database/")
diff --git a/configure.ac b/configure.ac
index 33913d181..065047cb9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -10,7 +10,9 @@ AC_CONFIG_MACRO_DIR([m4])
 
 # Checks for programs.
 AC_PROG_MAKE_SET
+AC_PROG_AWK
 AC_PROG_INSTALL
+AC_PROG_MKDIR_P
 AC_PROG_SED
 
 if test "x$GCC" = "xyes"; then
@@ -28,18 +30,35 @@ fi
 ])
 
 AC_ARG_WITH(rebar,
-	AS_HELP_STRING([--with-rebar=bin],[use the rebar/rebar3/mix binary specified]),
+	AS_HELP_STRING([--with-rebar=bin],[use as build tool the rebar/rebar3/mix binary specified]),
 [if test "$withval" = "yes" -o "$withval" = "no" -o "X$with_rebar" = "X"; then
-    rebar="rebar"
+    rebar="rebar3"
 else
     rebar="$with_rebar"
 fi
-], [rebar="rebar"])
+], [rebar="unconfigured"])
 
 AC_PATH_TOOL(ERL, erl, , [${extra_erl_path}$PATH])
 AC_PATH_TOOL(ERLC, erlc, , [${extra_erl_path}$PATH])
 AC_PATH_TOOL(EPMD, epmd, , [${extra_erl_path}$PATH])
 
+AC_PATH_TOOL(REBAR3, rebar3, , [${extra_erl_path}$PATH])
+AC_PATH_TOOL(ELIXIR, elixir, , [${extra_erl_path}$PATH])
+AC_PATH_TOOL(IEX, iex, , [${extra_erl_path}$PATH])
+AC_PATH_TOOL(MIX, mix, , [${extra_erl_path}$PATH])
+
+if test "$rebar" = unconfigured; then
+    if test "x$ELIXIR" = "x" -o "x$IEX" = "x" -o "x$MIX" = "x"; then
+        if test "x$REBAR3" = "x"; then
+            rebar="rebar3"
+        else
+            rebar=$REBAR3
+        fi
+    else
+        rebar=$MIX
+    fi
+fi
+
 AC_ERLANG_NEED_ERL
 AC_ERLANG_NEED_ERLC
 
@@ -84,7 +103,7 @@ AC_ARG_ENABLE(debug,
 esac],[if test "x$debug" = "x"; then debug=true; fi])
 
 AC_ARG_ENABLE(elixir,
-[AS_HELP_STRING([--enable-elixir],[enable Elixir support (default: no)])],
+[AS_HELP_STRING([--enable-elixir],[enable Elixir support in Rebar3 (default: no)])],
 [case "${enableval}" in
   yes) elixir=true ;;
   no)  elixir=false ;;
@@ -237,7 +256,7 @@ AC_ARG_ENABLE(system_deps,
 esac],[if test "x$system_deps" = "x"; then system_deps=false; fi])
 
 AC_ARG_ENABLE(tools,
-[AS_HELP_STRING([--enable-tools],[build development tools (default: no)])],
+[AS_HELP_STRING([--enable-tools],[build development tools: ejabberd-po, etop (default: no)])],
 [case "${enableval}" in
   yes) tools=true ;;
   no)  tools=false ;;
@@ -280,6 +299,8 @@ case "`uname`" in
   ;;
 esac
 
+AC_MSG_RESULT([build tool to use (change using --with-rebar): $rebar])
+
 AC_SUBST(roster_gateway_workaround)
 AC_SUBST(new_sql_schema)
 AC_SUBST(full_xml)
diff --git a/ejabberdctl.template b/ejabberdctl.template
index 0e221f473..eb16e3839 100755
--- a/ejabberdctl.template
+++ b/ejabberdctl.template
@@ -15,8 +15,8 @@ SCRIPT_DIR="$(cd "$(dirname "$SCRIPT")" && pwd -P)"
 # shellcheck disable=SC2034
 ERTS_VSN="{{erts_vsn}}"
 ERL="{{erl}}"
-IEX="{{bindir}}/iex"
 EPMD="{{epmd}}"
+IEX="{{iexpath}}"
 INSTALLUSER="{{installuser}}"
 
 # check the proper system user is used
@@ -175,8 +175,8 @@ livewarning()
         echo "Please be extremely cautious with your actions,"
         echo "and exit immediately if you are not completely sure."
         echo ""
-        echo "To exit this LIVE mode and stop ejabberd, press:"
-        echo "  q().  and press the Enter key"
+        echo "To exit and detach this shell from ejabberd, press:"
+        echo "  control+g and then q"
         echo ""
         echo "--------------------------------------------------------------------"
         echo "To bypass permanently this warning, add to ejabberdctl.cfg the line:"
@@ -187,6 +187,39 @@ livewarning()
     fi
 }
 
+check_etop_result()
+{
+    result=$?
+    if [ $result -eq 1 ] ; then
+        echo ""
+        echo "It seems there was some problem running 'ejabberdctl etop'."
+        echo "Is the error message something like this?"
+        echo "  Failed to load module 'etop' because it cannot be found..."
+        echo "Then probably ejabberd was compiled with development tools disabled."
+        echo "To use 'etop', recompile ejabberd with: ./configure --enable-tools"
+        echo ""
+        exit $result
+    fi
+}
+
+check_iex_result()
+{
+    result=$?
+    if [ $result -eq 127 ] ; then
+        echo ""
+        echo "It seems there was some problem finding 'iex' binary from Elixir."
+        echo "Probably ejabberd was compiled with Rebar3 and Elixir disabled, like:"
+        echo "  ./configure"
+        echo "which is equivalent to:"
+        echo "  ./configure --with-rebar=rebar3 --disable-elixir"
+        echo "To use 'iex', recompile ejabberd enabling Elixir or using Mix:"
+        echo "  ./configure --enable-elixir"
+        echo "  ./configure --with-rebar=mix"
+        echo ""
+        exit $result
+    fi
+}
+
 help()
 {
     echo ""
@@ -310,15 +343,18 @@ case $1 in
         set_dist_client
         exec_erl "$(uid top)" -hidden -remsh "$ERLANG_NODE" -s etop \
                  -output text
+        check_etop_result
         ;;
     iexdebug)
         debugwarning
         set_dist_client
         exec_iex "$(uid debug)" --remsh "$ERLANG_NODE"
+        check_iex_result
         ;;
     iexlive)
         livewarning
         exec_iex "$ERLANG_NODE" --erl "$EJABBERD_OPTS"
+        check_iex_result
         ;;
     ping)
         PEER=${2:-$ERLANG_NODE}
diff --git a/lib/ejabberd/config/ejabberd_module.ex b/lib/ejabberd/config/ejabberd_module.ex
index 6a74fe460..57fd8303c 100644
--- a/lib/ejabberd/config/ejabberd_module.ex
+++ b/lib/ejabberd/config/ejabberd_module.ex
@@ -60,7 +60,7 @@ defmodule Ejabberd.Config.EjabberdModule do
   defp fetch_and_store_repo_source_if_not_exists(path, repo) do
     unless File.exists?(path) do
       IO.puts "[info] Fetching: #{repo}"
-      :os.cmd('git clone #{repo} #{path}')
+      :os.cmd(~c"git clone #{repo} #{path}")
     end
   end
 
diff --git a/lib/mod_presence_demo.ex b/lib/mod_presence_demo.ex
index f41a53a31..c5be5bba5 100644
--- a/lib/mod_presence_demo.ex
+++ b/lib/mod_presence_demo.ex
@@ -2,19 +2,19 @@ defmodule ModPresenceDemo do
   use Ejabberd.Module
 
   def start(host, _opts) do
-    info('Starting ejabberd module Presence Demo')
+    info("Starting ejabberd module Presence Demo")
     Ejabberd.Hooks.add(:set_presence_hook, host, __MODULE__, :on_presence, 50)
     :ok
   end
 
   def stop(host) do
-    info('Stopping ejabberd module Presence Demo')
+    info("Stopping ejabberd module Presence Demo")
     Ejabberd.Hooks.delete(:set_presence_hook, host, __MODULE__, :on_presence, 50)
     :ok
   end
 
   def on_presence(user, _server, _resource, _packet) do
-    info('Receive presence for #{user}')
+    info("Receive presence for #{user}")
     :none
   end
 
@@ -27,7 +27,7 @@ defmodule ModPresenceDemo do
   end
 
   def mod_doc() do
-    %{:desc => 'This is just a demonstration.'}
+    %{:desc => "This is just a demonstration."}
   end
 
 end
diff --git a/mix.exs b/mix.exs
index c1af5a18a..8227791b9 100644
--- a/mix.exs
+++ b/mix.exs
@@ -8,7 +8,7 @@ defmodule Ejabberd.MixProject do
      elixir: elixir_required_version(),
      elixirc_paths: ["lib"],
      compile_path: ".",
-     compilers: [:asn1] ++ Mix.compilers(),
+     compilers: [:asn1, :yecc] ++ Mix.compilers(),
      erlc_options: erlc_options(),
      erlc_paths: ["asn1", "src"],
      # Elixir tests are starting the part of ejabberd they need
@@ -23,11 +23,11 @@ defmodule Ejabberd.MixProject do
   def version do
     case config(:vsn) do
       :false -> "0.0.0" # ./configure wasn't run: vars.config not created
-      '0.0' -> "0.0.0" # the full git repository wasn't downloaded
-      'latest.0' -> "0.0.0" # running 'docker-ejabberd/ecs/build.sh latest'
+      ~c"0.0" -> "0.0.0" # the full git repository wasn't downloaded
+      ~c"latest.0" -> "0.0.0" # running 'docker-ejabberd/ecs/build.sh latest'
       [_, _, ?., _, _] = x ->
         head = String.replace(:erlang.list_to_binary(x), ~r/\.0+([0-9])/, ".\\1")
-        <<head::binary, ".0">>
+        "#{head}.0"
       vsn -> String.replace(:erlang.list_to_binary(vsn), ~r/\.0+([0-9])/, ".\\1")
     end
   end
@@ -40,14 +40,14 @@ defmodule Ejabberd.MixProject do
 
   def application do
     [mod: {:ejabberd_app, []},
-     extra_applications: [:mix],
-     applications: [:idna, :inets, :kernel, :sasl, :ssl, :stdlib,
+     applications: [:idna, :inets, :kernel, :sasl, :ssl, :stdlib, :mix,
                     :base64url, :fast_tls, :fast_xml, :fast_yaml, :jiffy, :jose,
-                    :p1_utils, :stringprep, :syntax_tools, :yconf],
+                    :p1_utils, :stringprep, :syntax_tools, :yconf]
+     ++ cond_apps(),
      included_applications: [:mnesia, :os_mon,
                              :cache_tab, :eimp, :mqtree, :p1_acme,
                              :p1_oauth2, :pkix, :xmpp]
-     ++ cond_apps()]
+     ++ cond_included_apps()]
   end
 
   defp if_version_above(ver, okResult) do
@@ -68,20 +68,20 @@ defmodule Ejabberd.MixProject do
 
   defp erlc_options do
     # Use our own includes + includes from all dependencies
-    includes = ["include"] ++ deps_include(["fast_xml", "xmpp", "p1_utils"])
+    includes = ["include", deps_include()]
     result = [{:d, :ELIXIR_ENABLED}] ++
              cond_options() ++
              Enum.map(includes, fn (path) -> {:i, path} end) ++
-             if_version_above('20', [{:d, :DEPRECATED_GET_STACKTRACE}]) ++
-             if_version_above('20', [{:d, :HAVE_URI_STRING}]) ++
-             if_version_above('20', [{:d, :HAVE_ERL_ERROR}]) ++
-             if_version_below('21', [{:d, :USE_OLD_HTTP_URI}]) ++
-             if_version_below('22', [{:d, :LAGER}]) ++
-             if_version_below('21', [{:d, :NO_CUSTOMIZE_HOSTNAME_CHECK}]) ++
-             if_version_below('23', [{:d, :USE_OLD_CRYPTO_HMAC}]) ++
-             if_version_below('23', [{:d, :USE_OLD_PG2}]) ++
-             if_version_below('24', [{:d, :COMPILER_REPORTS_ONLY_LINES}]) ++
-             if_version_below('24', [{:d, :SYSTOOLS_APP_DEF_WITHOUT_OPTIONAL}])
+             if_version_above(~c"20", [{:d, :DEPRECATED_GET_STACKTRACE}]) ++
+             if_version_above(~c"20", [{:d, :HAVE_URI_STRING}]) ++
+             if_version_above(~c"20", [{:d, :HAVE_ERL_ERROR}]) ++
+             if_version_below(~c"21", [{:d, :USE_OLD_HTTP_URI}]) ++
+             if_version_below(~c"22", [{:d, :LAGER}]) ++
+             if_version_below(~c"21", [{:d, :NO_CUSTOMIZE_HOSTNAME_CHECK}]) ++
+             if_version_below(~c"23", [{:d, :USE_OLD_CRYPTO_HMAC}]) ++
+             if_version_below(~c"23", [{:d, :USE_OLD_PG2}]) ++
+             if_version_below(~c"24", [{:d, :COMPILER_REPORTS_ONLY_LINES}]) ++
+             if_version_below(~c"24", [{:d, :SYSTOOLS_APP_DEF_WITHOUT_OPTIONAL}])
     defines = for {:d, value} <- result, do: {:d, value}
     result ++ [{:d, :ALL_DEFS, defines}]
   end
@@ -119,8 +119,8 @@ defmodule Ejabberd.MixProject do
     ++ cond_deps()
   end
 
-  defp deps_include(deps) do
-    base = if Mix.Project.umbrella?() do
+  defp deps_include() do
+    if Mix.Project.umbrella?() do
       "../../deps"
     else
       case Mix.Project.deps_paths()[:ejabberd] do
@@ -128,7 +128,6 @@ defmodule Ejabberd.MixProject do
         _ -> ".."
       end
     end
-    Enum.map(deps, fn dep -> base<>"/#{dep}/include" end)
   end
 
   defp cond_deps do
@@ -136,7 +135,7 @@ defmodule Ejabberd.MixProject do
                          {config(:redis), {:eredis, "~> 1.2.0"}},
                          {config(:sip), {:esip, "~> 1.0"}},
                          {config(:zlib), {:ezlib, "~> 1.0"}},
-                         {if_version_below('22', true), {:lager, "~> 3.9.1"}},
+                         {if_version_below(~c"22", true), {:lager, "~> 3.9.1"}},
                          {config(:lua), {:luerl, "~> 1.0"}},
                          {config(:mysql), {:p1_mysql, git: "https://github.com/processone/p1_mysql.git", ref: "f685408b910c425b9905d4ddcdbedba717a5b48c"}},
                          {config(:pgsql), {:p1_pgsql, "~> 1.1"}},
@@ -146,10 +145,17 @@ defmodule Ejabberd.MixProject do
   end
 
   defp cond_apps do
+    for {:true, app} <- [{config(:stun), :stun},
+                         {config(:tools), :observer},
+                         {config(:tools), :runtime_tools}], do:
+      app
+  end
+
+  defp cond_included_apps do
     for {:true, app} <- [{config(:pam), :epam},
                          {config(:lua), :luerl},
                          {config(:redis), :eredis},
-                         {if_version_below('22', true), :lager},
+                         {if_version_below(~c"22", true), :lager},
                          {config(:mysql), :p1_mysql},
                          {config(:sip), :esip},
                          {config(:odbc), :odbc},
@@ -172,9 +178,15 @@ defmodule Ejabberd.MixProject do
   end
 
   defp vars do
-    case :file.consult("vars.config") do
+    filepath = case Application.fetch_env(:ejabberd, :vars_config_path) do
+      :error ->
+        "vars.config"
+      {:ok, path} ->
+        path
+    end
+    case :file.consult(filepath) do
       {:ok,config} -> config
-      _ -> [zlib: true]
+      _ -> [stun: true, zlib: true]
     end
   end
 
@@ -203,7 +215,7 @@ defmodule Ejabberd.MixProject do
           _ -> :ok
         end
         case Version.match?(System.version(), "< 1.11.4")
-          and :erlang.system_info(:otp_release) > '23' do
+          and :erlang.system_info(:otp_release) > ~c"23" do
           true ->
             IO.puts("ERROR: To build releases with Elixir lower than 1.11.4, Erlang/OTP lower than 24 is required.")
           _ -> :ok
@@ -239,6 +251,8 @@ defmodule Ejabberd.MixProject do
       config_dir: config(:config_dir),
       logs_dir: config(:logs_dir),
       spool_dir: config(:spool_dir),
+      vsn: config(:vsn),
+      iexpath: config(:iexpath),
       erl: config(:erl),
       epmd: config(:epmd),
       bindir: Path.join([config(:release_dir), "releases", version()]),
@@ -253,7 +267,7 @@ defmodule Ejabberd.MixProject do
     execute = fn(command) ->
       case function_exported?(System, :shell, 1) do
         true ->
-          System.shell(command)
+          System.shell(command, into: IO.stream())
         false ->
           :os.cmd(to_charlist(command))
       end
@@ -319,7 +333,7 @@ defmodule Ejabberd.MixProject do
     end
 
     case Mix.env() do
-      :dev -> execute.("REL_DIR_TEMP=$PWD/rel/overlays/ rel/setup-dev.sh")
+      :dev -> execute.("REL_DIR_TEMP=$PWD/rel/overlays/ rel/setup-dev.sh mix")
       _ -> :ok
     end
 
diff --git a/rebar b/rebar
index b6f011846..0b6871e70 100755
Binary files a/rebar and b/rebar differ
diff --git a/rebar.config b/rebar.config
index bca63ad41..6a715b586 100644
--- a/rebar.config
+++ b/rebar.config
@@ -27,8 +27,6 @@
         {eimp, ".*", {git, "https://github.com/processone/eimp", {tag, "1.0.22"}}},
         {if_var_true, tools,
          {ejabberd_po, ".*", {git, "https://github.com/processone/ejabberd-po", {branch, "main"}}}},
-        {if_var_true, elixir,
-         {elixir, ".*", {git, "https://github.com/elixir-lang/elixir", {tag, "v1.4.4"}}}},
         {if_var_true, pam,
          {epam, ".*", {git, "https://github.com/processone/epam", {tag, "1.0.14"}}}},
         {if_var_true, redis,
@@ -69,9 +67,6 @@
          {p1_pgsql, ".*", {git, "https://github.com/processone/p1_pgsql", {tag, "1.1.23"}}}},
         {p1_utils, ".*", {git, "https://github.com/processone/p1_utils", {tag, "1.0.25"}}},
         {pkix, ".*", {git, "https://github.com/processone/pkix", {tag, "1.0.9"}}},
-        {if_not_rebar3, %% Needed because modules are not fully migrated to new structure and mix
-         {if_var_true, elixir,
-          {rebar_elixir_plugin, ".*", {git, "https://github.com/processone/rebar_elixir_plugin", "0.1.0"}}}},
         {if_var_true, sqlite,
          {sqlite3, ".*", {git, "https://github.com/processone/erlang-sqlite3", {tag, "1.1.14"}}}},
         {stringprep, ".*", {git, "https://github.com/processone/stringprep", {tag, "1.0.29"}}},
@@ -81,7 +76,7 @@
         {yconf, ".*", {git, "https://github.com/processone/yconf", {tag, "1.0.15"}}}
        ]}.
 
-{gitonly_deps, [elixir]}.
+{gitonly_deps, [ejabberd_po]}.
 
 {if_var_true, latest_deps,
  {floating_deps, [cache_tab,
@@ -146,23 +141,26 @@
             {if_var_true, stun, {d, 'STUN'}},
             {src_dirs, [src,
                         {if_rebar3, sql},
-                        {if_var_true, tools, tools},
-                        {if_var_true, elixir, include}]}]}.
+                        {if_var_true, tools, tools}]}]}.
 
-{if_rebar3, {plugins, [rebar3_hex, {provider_asn1, "0.2.0"}]}}.
+{if_rebar3, {plugins, [rebar3_hex, {provider_asn1, "0.2.0"},
+                       %% Protocol consolidation doesn't work correctly in upstream rebar_mix, see
+                       %% https://github.com/Supersonido/rebar_mix/issues/27#issuecomment-894873335
+                       %% Let's use this fixed rebar_mix fork, see its PR:
+                       %% https://github.com/Supersonido/rebar_mix/pull/31
+                       {if_var_true, elixir, {rebar_mix, ".*",
+                                              {git, "https://github.com/bsanyi/rebar_mix.git",
+                                               {branch, "consolidation_fix"}}}
+                       }]}}.
 {if_rebar3, {project_plugins, [configure_deps]}}.
 {if_not_rebar3, {plugins, [
-                           deps_erl_opts, override_deps_versions2, override_opts, configure_deps,
-                           {if_var_true, elixir, rebar_elixir_compiler},
-                           {if_var_true, elixir, rebar_exunit}
+                           deps_erl_opts, override_deps_versions2, override_opts, configure_deps
                           ]}}.
 
 {if_rebar3, {if_var_true, elixir,
-              {project_app_dirs, [".", "elixir/lib"]}}}.
-{if_not_rebar3, {if_var_true, elixir,
-              {lib_dirs, ["deps/elixir/lib"]}}}.
-{if_var_true, elixir,
-              {src_dirs, ["include"]}}.
+    {provider_hooks, [
+      {post, [{compile, {mix, consolidate_protocols}}]}
+    ]}}}.
 
 {sub_dirs, ["rel"]}.
 
@@ -255,6 +253,12 @@
                    {mkdir, "conf"},
                    {copy, "rel/files/erl", "erts-\{\{erts_vsn\}\}/bin/erl"},
                    {template, "ejabberdctl.template", "bin/ejabberdctl"},
+                   {copy, "_build/default/lib/ejabberd/ebin/Elixir.*", "lib/ejabberd-{{release_version}}/ebin/"},
+                   {copy, "{{base_dir}}/consolidated/*", "lib/ejabberd-{{release_version}}/ebin/"},
+                   {copy, "rel/overlays/iex", "releases/{{release_version}}/"},
+                   {if_var_true, elixir,
+                    {template, "rel/overlays/elixir", "releases/{{release_version}}/elixir"}
+                   },
                    {copy, "inetrc", "conf/inetrc"},
                    {copy, "tools/captcha*.sh", "lib/ejabberd-\{\{release_version\}\}/priv/bin/"},
                    {copy, "rel/files/install_upgrade.escript", "bin/install_upgrade.escript"}]}
@@ -268,7 +272,7 @@
                             {overlay, [{copy, "sql/*", "lib/ejabberd-\{\{release_version\}\}/priv/sql/"},
                                        {copy, "ejabberdctl.cfg.example", "conf/ejabberdctl.cfg"},
                                        {copy, "ejabberd.yml.example", "conf/ejabberd.yml"}]}]}]},
-            {dev, [{post_hooks, [{release, "rel/setup-dev.sh"}]},
+            {dev, [{post_hooks, [{release, "rel/setup-dev.sh rebar3"}]},
                    {relx, [{debug_info, keep},
                            {dev_mode, true},
                            {include_erts, true},
diff --git a/rebar3 b/rebar3
index bf1935ce6..e903655b8 100755
Binary files a/rebar3 and b/rebar3 differ
diff --git a/rel/reltool.config.script b/rel/reltool.config.script
index b7ccdf9c5..fea4d6619 100644
--- a/rel/reltool.config.script
+++ b/rel/reltool.config.script
@@ -53,6 +53,8 @@ OTPApps = RequiredOTPApps ++ ConfiguredOTPApps,
 
 DepApps = lists:usort(lists:flatten(GetDeps(filename:join(TopDir, "rebar.config"), GetDeps))),
 
+SysVer = erlang:system_info(otp_release),
+
 Sys = [{lib_dirs, []},
        {erts, [{mod_cond, derived}, {app_file, strip}]},
        {app_file, strip},
@@ -70,13 +72,17 @@ Sys = [{lib_dirs, []},
        {boot_rel, "ejabberd"},
        {profile, embedded},
        {incl_cond, exclude},
-       {excl_archive_filters, [".*"]}, %% Do not archive built libs
        {excl_sys_filters, ["^bin/.*", "^erts.*/bin/(dialyzer|typer)",
                            "^erts.*/(doc|info|include|lib|man|src)"]},
        {excl_app_filters, ["\.gitignore"]},
        {app, stdlib, [{incl_cond, include}]},
        {app, kernel, [{incl_cond, include}]},
        {app, ejabberd, [{incl_cond, include}, {lib_dir, ".."}]}]
+++ if SysVer < "26" ->
+          [{excl_archive_filters, [".*"]}]; %% Do not archive built libs
+      true ->
+          []
+   end
 ++ lists:map(
      fun(App) ->
              {app, App, [{incl_cond, include},
diff --git a/rel/setup-dev.sh b/rel/setup-dev.sh
index d9d94a2d0..af3875cf0 100755
--- a/rel/setup-dev.sh
+++ b/rel/setup-dev.sh
@@ -23,5 +23,14 @@ sed -i "s|#' POLL|EJABBERD_BYPASS_WARNINGS=true\n\n#' POLL|g" ejabberdctl.cfg.ex
 
 echo ""
 echo "===> Some example ways to start this ejabberd dev:"
-echo "     _build/dev/rel/ejabberd/bin/ejabberd console"
 echo "     _build/dev/rel/ejabberd/bin/ejabberdctl live"
+case "$1" in
+    "rebar3")
+        echo "     _build/dev/rel/ejabberd/bin/ejabberd console"
+        ;;
+    "mix")
+        echo "     RELEASE_NODE=ejabberd@localhost _build/dev/rel/ejabberd/bin/ejabberd start"
+        ;;
+    "*")
+        ;;
+esac
diff --git a/src/ejabberd.app.src.script b/src/ejabberd.app.src.script
index 4c8745146..83a639095 100644
--- a/src/ejabberd.app.src.script
+++ b/src/ejabberd.app.src.script
@@ -1,13 +1,21 @@
-Vars = case file:consult(filename:join([filename:dirname(SCRIPT), "..", "vars.config"])) of
+{Vars, ElixirApps} = case file:consult(filename:join([filename:dirname(SCRIPT), "..", "vars.config"])) of
     {ok, Terms} ->
         Backends = [mssql, mysql, odbc, pgsql, redis, sqlite],
         EBs = lists:filter(fun(Backend) -> lists:member({Backend, true}, Terms) end, Backends),
-        [lists:keyfind(description, 1, Terms),
+        Elixirs = case lists:keyfind(elixir, 1, Terms) of
+            {elixir, true} -> [elixir, iex, logger, mix];
+            _ -> []
+        end,
+        Tools = case lists:keyfind(tools, 1, Terms) of
+            {tools, true} -> [observer, runtime_tools]; % for `ejabberdctl etop`
+            _ -> []
+        end,
+        {[lists:keyfind(description, 1, Terms),
          lists:keyfind(vsn, 1, Terms),
          {env, [{enabled_backends, EBs}]}
-        ];
+        ], Elixirs ++ Tools};
     _Err ->
-        []
+        {[], []}
     end,
 
 {application, ejabberd,
@@ -27,7 +35,7 @@ Vars = case file:consult(filename:join([filename:dirname(SCRIPT), "..", "vars.co
      pkix,
      stringprep,
      yconf,
-     xmpp]},
+     xmpp | ElixirApps]},
   {mod, {ejabberd_app, []}}]}.
 
 %% Local Variables:
diff --git a/src/ejabberd.erl b/src/ejabberd.erl
index e90c8eb74..578a06d91 100644
--- a/src/ejabberd.erl
+++ b/src/ejabberd.erl
@@ -132,7 +132,7 @@ check_apps() ->
       fun() ->
 	      Apps = [ejabberd |
 		      [App || {App, _, _} <- application:which_applications(),
-			      App /= ejabberd]],
+			      App /= ejabberd, App /= hex]],
 	      ?DEBUG("Checking consistency of applications: ~ts",
 		     [misc:join_atoms(Apps, <<", ">>)]),
 	      misc:peach(
diff --git a/src/ejabberd_logger.erl b/src/ejabberd_logger.erl
index 736d6c20c..897a4352e 100644
--- a/src/ejabberd_logger.erl
+++ b/src/ejabberd_logger.erl
@@ -340,8 +340,20 @@ progress_filter(#{level:=info,msg:={report,#{label:={_,progress}}}} = Event, _)
 progress_filter(Event, _) ->
     Event.
 
+-ifdef(ELIXIR_ENABLED).
+console_template() ->
+    case (false /= code:is_loaded('Elixir.Logger'))
+        andalso
+        lists:keymember(default_formatter, 1, 'Elixir.Logger':module_info(exports)) of
+        true ->
+            [date, " ", time, " [", level, "] ", message, "\n"];
+        false ->
+            [time, " [", level, "] " | msg()]
+    end.
+-else.
 console_template() ->
     [time, " [", level, "] " | msg()].
+-endif.
 
 file_template() ->
     [time, " [", level, "] ", pid,
diff --git a/src/ext_mod.erl b/src/ext_mod.erl
index ddab4407c..922b4da65 100644
--- a/src/ext_mod.erl
+++ b/src/ext_mod.erl
@@ -603,8 +603,8 @@ compile(LibDir) ->
     Er = [compile_erlang_file(Bin, File, Options)
           || File <- filelib:wildcard(Src++"/*.erl")],
     Ex = [compile_elixir_file(Bin, File)
-          || File <- filelib:wildcard(Lib ++ "/*.ex")],
-    compile_result(Er++Ex).
+          || File <- filelib:wildcard(Lib ++ "/**/*.ex")],
+    compile_result(lists:flatten([Er, Ex])).
 
 compile_c_files(LibDir) ->
     case file:read_file_info(filename:join(LibDir, "c_src/Makefile")) of
@@ -673,7 +673,7 @@ compile_elixir_file(Dest, File) when is_list(Dest) and is_list(File) ->
 
 compile_elixir_file(Dest, File) ->
   try 'Elixir.Kernel.ParallelCompiler':files_to_path([File], Dest, []) of
-    [Module] -> {ok, Module}
+    Modules when is_list(Modules) -> {ok, Modules}
   catch
     _ -> {error, {compilation_failed, File}}
   end.
diff --git a/vars.config.in b/vars.config.in
index 88cc581eb..d0b4a392a 100644
--- a/vars.config.in
+++ b/vars.config.in
@@ -55,6 +55,7 @@
 {installuser, "@INSTALLUSER@"}.
 {erl, "{{erts_dir}}/bin/erl"}.
 {epmd, "{{erts_dir}}/bin/epmd"}.
+{iexpath, "{{release_dir}}/releases/{{vsn}}/iex"}.
 {localstatedir, "{{release_dir}}/var"}.
 {libdir, "{{release_dir}}/lib"}.
 {docdir, "{{release_dir}}/doc"}.