diff --git a/Dockerfile b/Dockerfile
index a34143c..fbf0f5e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,20 +13,18 @@ RUN gcc -static -o membarrier_check membarrier_check.c
 RUN strip membarrier_check
 
 # Pull base image.
-FROM jlesage/baseimage-gui:alpine-3.15-v3.5.8
+FROM jlesage/baseimage-gui:alpine-3.16-v4.0.1
 
 # Docker image version is provided via build arg.
-ARG DOCKER_IMAGE_VERSION=unknown
+ARG DOCKER_IMAGE_VERSION=
 
 # Define software versions.
-ARG FIREFOX_VERSION=94.0-r0
-ARG YAD_VERSION=7.3
+ARG FIREFOX_VERSION=101.0.1-r0
 ARG JSONLZ4_VERSION=c4305b8
 ARG LZ4_VERSION=1.8.1.2
 #ARG PROFILE_CLEANER_VERSION=2.36
 
 # Define software download URLs.
-ARG YAD_URL=https://github.com/v1cont/yad/releases/download/v${YAD_VERSION}/yad-${YAD_VERSION}.tar.xz
 ARG JSONLZ4_URL=https://github.com/avih/dejsonlz4/archive/${JSONLZ4_VERSION}.tar.gz
 ARG LZ4_URL=https://github.com/lz4/lz4/archive/v${LZ4_VERSION}.tar.gz
 #ARG PROFILE_CLEANER_URL=https://github.com/graysky2/profile-cleaner/raw/v${PROFILE_CLEANER_VERSION}/common/profile-cleaner.in
@@ -64,49 +62,13 @@ RUN \
 #            --upgrade firefox=${FIREFOX_VERSION}
      add-pkg firefox=${FIREFOX_VERSION}
 
-# Install YAD.
-# NOTE: YAD is compiled manually because the version on the Alpine repository
-#       pulls too much dependencies.
-RUN \
-    # Install packages needed by the build.
-    add-pkg --virtual build-dependencies \
-        build-base \
-        curl \
-        intltool \
-        gtk+3.0-dev \
-        && \
-    # Set same default compilation flags as abuild.
-    export CFLAGS="-Os -fomit-frame-pointer" && \
-    export CXXFLAGS="$CFLAGS" && \
-    export CPPFLAGS="$CFLAGS" && \
-    export LDFLAGS="-Wl,--as-needed" && \
-    # Download.
-    mkdir yad && \
-    echo "Downloading YAD package..." && \
-    curl -# -L ${YAD_URL} | tar xJ --strip 1  -C yad && \
-    # Compile.
-    cd yad && \
-    ./configure \
-        --prefix=/usr \
-        --enable-standalone \
-        --disable-icon-browser \
-        --disable-html \
-        --disable-pfd \
-        && \
-    make && make install && \
-    strip /usr/bin/yad && \
-    cd .. && \
-    # Cleanup.
-    del-pkg build-dependencies && \
-    rm -rf /tmp/* /tmp/.[!.]*
-
 # Install extra packages.
 RUN \
     add-pkg \
-        desktop-file-utils \
-        adwaita-icon-theme \
+        # Icons used by folder/file selection window (when saving as).
+        gnome-icon-theme \
+        # A font is needed.
         ttf-dejavu \
-        ffmpeg-libs \
         # The following package is used to send key presses to the X process.
         xdotool
 
@@ -141,15 +103,6 @@ RUN \
     sed-patch 's|LOG_FILES=|LOG_FILES=/config/log/firefox/error.log|' /etc/logmonitor/logmonitor.conf && \
     sed-patch 's|STATUS_FILES=|STATUS_FILES=/tmp/.firefox_shm_check,/tmp/.firefox_membarrier_check|' /etc/logmonitor/logmonitor.conf
 
-# Adjust the openbox config.
-RUN \
-    # Maximize only the main window.
-    sed-patch 's/<application type="normal">/<application type="normal" title="Mozilla Firefox">/' \
-        /etc/xdg/openbox/rc.xml && \
-    # Make sure the main window is always in the background.
-    sed-patch '/<application type="normal" title="Mozilla Firefox">/a \    <layer>below</layer>' \
-        /etc/xdg/openbox/rc.xml
-
 # Generate and install favicons.
 RUN \
     APP_ICON_URL=https://github.com/jlesage/docker-templates/raw/master/jlesage/images/firefox-icon.png && \
@@ -159,8 +112,12 @@ RUN \
 COPY rootfs/ /
 COPY --from=membarrier /tmp/membarrier_check /usr/bin/
 
-# Set environment variables.
-ENV APP_NAME="Firefox"
+# Set internal environment variables.
+RUN \
+    set-cont-env APP_NAME "Firefox" && \
+    set-cont-env APP_VERSION "$FIREFOX_VERSION" && \
+    set-cont-env DOCKER_IMAGE_VERSION "$DOCKER_IMAGE_VERSION" && \
+    true
 
 # Define mountable directories.
 VOLUME ["/config"]
@@ -169,6 +126,6 @@ VOLUME ["/config"]
 LABEL \
       org.label-schema.name="firefox" \
       org.label-schema.description="Docker container for Firefox" \
-      org.label-schema.version="$DOCKER_IMAGE_VERSION" \
+      org.label-schema.version="${DOCKER_IMAGE_VERSION:-unknown}" \
       org.label-schema.vcs-url="https://github.com/jlesage/docker-firefox" \
       org.label-schema.schema-version="1.0"
diff --git a/rootfs/etc/cont-init.d/check-snd.sh b/rootfs/etc/cont-init.d/55-check-snd.sh
similarity index 73%
rename from rootfs/etc/cont-init.d/check-snd.sh
rename to rootfs/etc/cont-init.d/55-check-snd.sh
index dcbdfb1..1e917f3 100755
--- a/rootfs/etc/cont-init.d/check-snd.sh
+++ b/rootfs/etc/cont-init.d/55-check-snd.sh
@@ -1,22 +1,18 @@
-#!/usr/bin/with-contenv sh
+#!/bin/sh
 
 set -e # Exit immediately if a command exits with a non-zero status.
 set -u # Treat unset variables as an error.
 
-log() {
-    echo "[cont-init.d] $(basename $0): $*"
-}
-
 SND_DEV="/dev/snd"
 
 if [ ! -d "$SND_DEV" ]; then
-    log "sound not supported: device $SND_DEV not exposed to the container."
+    echo "sound not supported: device $SND_DEV not exposed to the container."
     exit 0
 fi
 
 # Save the associated group.
 SND_GRP="$(find "$SND_DEV" -maxdepth 1 -not -type d -exec stat -c "%g" {} \; | sort -u | tail -n1)"
-log "sound device group $SND_GRP."
+echo "sound device group $SND_GRP."
 if [ -f /var/run/s6/container_environment/SUP_GROUP_IDS ]; then
     echo -n "," >> /var/run/s6/container_environment/SUP_GROUP_IDS
 fi
diff --git a/rootfs/etc/cont-init.d/firefox-set-prefs-from-env.sh b/rootfs/etc/cont-init.d/55-firefox-set-prefs-from-env.sh
similarity index 73%
rename from rootfs/etc/cont-init.d/firefox-set-prefs-from-env.sh
rename to rootfs/etc/cont-init.d/55-firefox-set-prefs-from-env.sh
index 2898de2..8bf288c 100755
--- a/rootfs/etc/cont-init.d/firefox-set-prefs-from-env.sh
+++ b/rootfs/etc/cont-init.d/55-firefox-set-prefs-from-env.sh
@@ -1,15 +1,11 @@
-#!/usr/bin/with-contenv sh
+#!/bin/sh
 
 set -e
 
-log() {
-    echo "[cont-init.d] $(basename $0): $*"
-}
-
 PREF_FILE="${1:-/config/profile/prefs.js}"
 
 if [ -z "$PREF_FILE" ]; then
-    log "ERROR: Preference file not set."
+    echo "ERROR: Preference file not set."
     exit 1
 fi
 
@@ -22,7 +18,7 @@ do
     EVAL="$(echo "$ENV" | cut -d '=' -f2-)"
 
     if [ -z "$EVAL" ]; then
-        log "Skipping environment variable '$ENAME': no value set."
+        echo "Skipping environment variable '$ENAME': no value set."
         continue
     fi
 
@@ -36,13 +32,13 @@ do
     fi 
 
     if [ "$PVAL" = "UNSET" ]; then
-        log "Removing preference '$PNAME'..."
+        echo "Removing preference '$PNAME'..."
         sed -i "/user_pref(\"$PNAME\",.*);/d" "$PREF_FILE"
     elif grep -q "user_pref(\"$PNAME\"," "$PREF_FILE"; then
-        log "Setting preference '$PNAME'..."
+        echo "Setting preference '$PNAME'..."
         sed -i "s/user_pref(\"$PNAME\",.*);/user_pref(\"$PNAME\", $PVAL);/" "$PREF_FILE"
     else
-        log "Setting new preference '$PNAME'..."
+        echo "Setting new preference '$PNAME'..."
         echo "user_pref(\"$PNAME\", $PVAL);" >> "$PREF_FILE"
     fi
 done
diff --git a/rootfs/etc/cont-init.d/firefox.sh b/rootfs/etc/cont-init.d/55-firefox.sh
similarity index 91%
rename from rootfs/etc/cont-init.d/firefox.sh
rename to rootfs/etc/cont-init.d/55-firefox.sh
index eb6c90d..5adde96 100755
--- a/rootfs/etc/cont-init.d/firefox.sh
+++ b/rootfs/etc/cont-init.d/55-firefox.sh
@@ -1,19 +1,15 @@
-#!/usr/bin/with-contenv sh
+#!/bin/sh
 
 set -e # Exit immediately if a command exits with a non-zero status.
 set -u # Treat unset variables as an error.
 
-log() {
-    echo "[cont-init.d] $(basename $0): $*"
-}
-
 # Make sure some directories are created.
 mkdir -p /config/downloads
 mkdir -p /config/log/firefox
 
 # Generate machine id.
 if [ ! -f /etc/machine-id ]; then
-    log "generating machine-id..."
+    echo "generating machine-id..."
     cat /proc/sys/kernel/random/uuid | tr -d '-' > /etc/machine-id
 fi
 
@@ -24,12 +20,14 @@ if [ "$SHM_SIZE_MB" -eq 64 ]; then
 else
    echo 'SHM_CHECK_PASS' > /tmp/.firefox_shm_check
 fi
+chown $USER_ID:$GROUP_ID /tmp/.firefox_shm_check
 
 if /usr/bin/membarrier_check 2>/dev/null; then
    echo 'MEMBARRIER_CHECK_PASS' > /tmp/.firefox_membarrier_check
 else
    echo 'MEMBARRIER_CHECK_FAIL' > /tmp/.firefox_membarrier_check
 fi
+chown $USER_ID:$GROUP_ID /tmp/.firefox_membarrier_check
 
 # Clean/optimize Firefox databases.
 #if [ -d /config/.mozilla/firefox ] && [ -d /config/profile ]; then
@@ -53,7 +51,7 @@ if [ -n "$(ls /config/profile/sessionstore-backups/*.jsonlz4 2>/dev/null)" ]; th
         if ! diff "$WORKDIR"/json "$WORKDIR"/json.orig >/dev/null; then
             jsonlz4 "$WORKDIR"/json "$WORKDIR"/jsonlz4
             mv "$WORKDIR"/jsonlz4 "$FILE"
-            log "fixed display size in $FILE."
+            echo "fixed display size in $FILE."
         fi
 
         rm -r "$WORKDIR"
diff --git a/rootfs/etc/jwm/main-window-selection.jwmrc b/rootfs/etc/jwm/main-window-selection.jwmrc
new file mode 100644
index 0000000..002f074
--- /dev/null
+++ b/rootfs/etc/jwm/main-window-selection.jwmrc
@@ -0,0 +1,2 @@
+<Type>normal</Type>
+<Name>^Navigator</Name>
diff --git a/rootfs/etc/logmonitor/notifications.d/membarrier/desc b/rootfs/etc/logmonitor/notifications.d/membarrier/desc
index 70f9767..648f482 100755
--- a/rootfs/etc/logmonitor/notifications.d/membarrier/desc
+++ b/rootfs/etc/logmonitor/notifications.d/membarrier/desc
@@ -1,2 +1,2 @@
-#!/usr/bin/with-contenv sh
+#!/bin/sh
 echo "$APP_NAME is likely to crash because it requires the membarrier system call.  See the documentation of this Docker container to find out how this system call can be allowed."
diff --git a/rootfs/etc/logmonitor/notifications.d/membarrier/title b/rootfs/etc/logmonitor/notifications.d/membarrier/title
index fd47e05..6f2e0da 100755
--- a/rootfs/etc/logmonitor/notifications.d/membarrier/title
+++ b/rootfs/etc/logmonitor/notifications.d/membarrier/title
@@ -1,2 +1,2 @@
-#!/usr/bin/with-contenv sh
+#!/bin/sh
 echo "$APP_NAME requires the membarrier system call."
diff --git a/rootfs/etc/logmonitor/notifications.d/shm_size/desc b/rootfs/etc/logmonitor/notifications.d/shm_size/desc
index bfa4271..9b9080b 100755
--- a/rootfs/etc/logmonitor/notifications.d/shm_size/desc
+++ b/rootfs/etc/logmonitor/notifications.d/shm_size/desc
@@ -1,2 +1,2 @@
-#!/usr/bin/with-contenv sh
+#!/bin/sh
 echo "$APP_NAME is likely to crash because of the lack of shared memory.  Size of shared memory needs to be increased.  See the documentation of the Docker container to find out how this can be done."
diff --git a/rootfs/etc/logmonitor/notifications.d/shm_size/title b/rootfs/etc/logmonitor/notifications.d/shm_size/title
index 3d5d615..39a42c1 100755
--- a/rootfs/etc/logmonitor/notifications.d/shm_size/title
+++ b/rootfs/etc/logmonitor/notifications.d/shm_size/title
@@ -1,2 +1,2 @@
-#!/usr/bin/with-contenv sh
+#!/bin/sh
 echo "$APP_NAME lacks of shared memory."
diff --git a/rootfs/etc/logmonitor/notifications.d/tab_crash/desc b/rootfs/etc/logmonitor/notifications.d/tab_crash/desc
index 7c8f846..258b037 100755
--- a/rootfs/etc/logmonitor/notifications.d/tab_crash/desc
+++ b/rootfs/etc/logmonitor/notifications.d/tab_crash/desc
@@ -1,2 +1,2 @@
-#!/usr/bin/with-contenv sh
+#!/bin/sh
 echo "A $APP_NAME tab crashed because of the lack of shared memory.  Size of shared memory needs to be increased.  See the documentation of this Docker container to find out how this can be done."
diff --git a/rootfs/etc/logmonitor/notifications.d/tab_crash/title b/rootfs/etc/logmonitor/notifications.d/tab_crash/title
index 3d5d615..39a42c1 100755
--- a/rootfs/etc/logmonitor/notifications.d/tab_crash/title
+++ b/rootfs/etc/logmonitor/notifications.d/tab_crash/title
@@ -1,2 +1,2 @@
-#!/usr/bin/with-contenv sh
+#!/bin/sh
 echo "$APP_NAME lacks of shared memory."
diff --git a/rootfs/etc/services.d/app/kill b/rootfs/etc/services.d/app/kill
new file mode 100755
index 0000000..7a99f23
--- /dev/null
+++ b/rootfs/etc/services.d/app/kill
@@ -0,0 +1,14 @@
+#!/bin/sh
+#
+# When receiving SIGTERM, Firefox doesn't qui immediately and instead ask for
+# confirmation.  Instead, terminate Firefox by sending the CTRL+q key presses.
+#
+
+set -e # Exit immediately if a command exits with a non-zero status.
+set -u # Treat unset variables as an error.
+
+xdotool key "Escape"
+xdotool key "ctrl+q"
+
+# vim:ft=sh:ts=4:sw=4:et:sts=4
+
diff --git a/rootfs/startapp.sh b/rootfs/startapp.sh
index bb0bd3f..05d18c9 100755
--- a/rootfs/startapp.sh
+++ b/rootfs/startapp.sh
@@ -1,9 +1,9 @@
-#!/usr/bin/with-contenv sh
+#!/bin/sh
 
 set -e # Exit immediately if a command exits with a non-zero status.
 set -u # Treat unset variables as an error.
 
 export HOME=/config
 mkdir -p /config/profile
-firefox --version
-exec /usr/bin/firefox_wrapper --profile /config/profile --setDefaultBrowser >> /config/log/firefox/output.log 2>> /config/log/firefox/error.log
+/usr/bin/firefox --version
+exec /usr/bin/firefox  --profile /config/profile --setDefaultBrowser >> /config/log/firefox/output.log 2>> /config/log/firefox/error.log
diff --git a/rootfs/usr/bin/firefox_wrapper b/rootfs/usr/bin/firefox_wrapper
deleted file mode 100755
index f8d6844..0000000
--- a/rootfs/usr/bin/firefox_wrapper
+++ /dev/null
@@ -1,60 +0,0 @@
-#!/bin/sh
-
-#
-# This small wrapper is used to gracefully terminate Firefox.  It prevents
-# the application to receive termination signals directly.  Instead, the wrapper
-# traps signals and send CTRL+q key presses to Firefox.
-#
-
-FF_PID=0
-
-# Gracefully terminate Firefox.  This function is called when this script
-# receives a termination signal (SIGKILL, SIGINT or SIGQUIT).
-kill_firefox() {
-    # Gracefully close Firefox.
-    echo "Terminating Firefox..."
-    xdotool key "Escape"
-    xdotool key "ctrl+q"
-
-    # And wait for its termination.
-    if [ "$FF_PID" -ne 0 ]; then
-        wait $FF_PID
-        exit $?
-    fi
-}
-trap 'kill_firefox' TERM INT QUIT
-
-# This function is called when this script exits.  It makes sure that Firefox is
-# fully closed by waiting for all its processes to terminate.
-exit_wrapper() {
-    echo "Waiting for Firefox to completely terminate..."
-    TIMEOUT=10
-    while firefox_running && [ "$TIMEOUT" -gt 0 ]; do
-        TIMEOUT="$(expr "$TIMEOUT" - 1)"
-        sleep 1
-    done
-
-    if [ "$TIMEOUT" -gt 0 ]; then
-        echo "Firefox terminated."
-    else
-        echo "WARNING: Firefox still not terminated."
-    fi
-}
-trap 'exit_wrapper' EXIT
-
-firefox_running() {
-    ps | grep -v grep | grep -q '/usr/lib/firefox'
-}
-
-# Make sure to terminate any existing instance.
-if firefox_running; then
-    kill_firefox
-fi
-
-# Start Firefox in background.
-/usr/bin/firefox "$@" &
-
-# And wait for its termination.
-FF_PID=$!
-wait $FF_PID
-exit $?