diff --git a/docker-compose.yml b/docker-compose.yml
index 9d138f85..f235fac7 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,209 +1,210 @@
 version: '3'
 services:
   coturn:
     container_name: kolab-coturn
     healthcheck:
       interval: 10s
       test: "kill -0 $$(cat /tmp/turnserver.pid)"
       timeout: 5s
       retries: 30
     environment:
       - DB_NAME=${OPENVIDU_COTURN_REDIS_DATABASE}
       - DB_PASSWORD=${OPENVIDU_COTURN_REDIS_PASSWORD}
       - REDIS_IP=${OPENVIDU_COTURN_REDIS_IP}
       - TURN_PUBLIC_IP=${OPENVIDU_COTURN_IP}
       - TURN_LISTEN_PORT=3478
     hostname: sturn.mgmt.com
     image: openvidu/openvidu-coturn:1.0.0
     network_mode: host
     restart: on-failure
     tty: true
   kolab:
     build:
       context: ./docker/kolab/
     container_name: kolab
     depends_on:
       - mariadb
     extra_hosts:
       - "kolab.mgmt.com:127.0.0.1"
     environment:
       - DB_HOST=${DB_HOST}
       - DB_ROOT_PASSWORD=Welcome2KolabSystems
     healthcheck:
       interval: 10s
       test: test -f /tmp/kolab-init.done
       timeout: 5s
       retries: 30
     hostname: kolab.mgmt.com
     image: kolab
     network_mode: host
     tmpfs:
       - /run
       - /tmp
       - /var/run
       - /var/tmp
     tty: true
     volumes:
+      - ./ext/:/src/:ro
       - /etc/letsencrypt/:/etc/letsencrypt/:ro
       - ./docker/certs/ca.cert:/etc/pki/tls/certs/ca.cert:ro
       - ./docker/certs/ca.cert:/etc/pki/ca-trust/source/anchors/ca.cert:ro
       - ./docker/certs/kolab.hosted.com.cert:/etc/pki/tls/certs/kolab.hosted.com.cert
       - ./docker/certs/kolab.hosted.com.key:/etc/pki/tls/certs/kolab.hosted.com.key
       - ./docker/certs/kolab.mgmt.com.cert:/etc/pki/tls/certs/kolab.mgmt.com.cert
       - ./docker/certs/kolab.mgmt.com.key:/etc/pki/tls/certs/kolab.mgmt.com.key
       - ./docker/kolab/utils:/root/utils:ro
       - ./src/.env:/.dockerenv:ro
       - /sys/fs/cgroup:/sys/fs/cgroup:ro
   kurento-media-server:
     build:
       context: ./docker/kurento-media-server/
     container_name: kolab-kurento-media-server
     environment:
       - GST_DEBUG=3,Kurento*:4,kms*:4,sdp*:4,webrtc*:4,*rtpendpoint:4,rtp*handler:4,rtpsynchronizer:4,agnosticbin:4
     hostname: kurento-media-server.hosted.com
     image: apheleia/kurento-media-server:6.15.0
     network_mode: host
   mariadb:
     container_name: kolab-mariadb
     environment:
       MYSQL_ROOT_PASSWORD: Welcome2KolabSystems
       TZ: "+02:00"
     healthcheck:
       interval: 10s
       test: test -e /var/run/mysqld/mysqld.sock
       timeout: 5s
       retries: 30
     image: mariadb
     network_mode: host
   nginx:
     build:
       context: ./docker/nginx/
       args:
         APP_WEBSITE_DOMAIN: ${APP_WEBSITE_DOMAIN:?err}
     healthcheck:
       interval: 10s
       test: ["CMD-SHELL", "curl -so /dev/null http://localhost/ || exit 1"]
       timeout: 5s
       retries: 30
     container_name: kolab-nginx
     hostname: nginx.hosted.com
     image: kolab-nginx
     network_mode: host
     tmpfs:
       - /run
       - /tmp
       - /var/run
       - /var/tmp
     tty: true
     volumes:
       - ./docker/certs/imap.hosted.com.cert:/etc/pki/tls/certs/imap.hosted.com.cert
       - ./docker/certs/imap.hosted.com.key:/etc/pki/tls/private/imap.hosted.com.key
   openvidu:
     build:
       context: ./docker/openvidu/
     container_name: kolab-openvidu
     depends_on:
       - kurento-media-server
     environment:
       - APP_DOMAIN=${APP_DOMAIN}
       - CERTIFICATE_TYPE=letsencrypt
       - COTURN_IP=${OPENVIDU_COTURN_IP}
       - COTURN_REDIS_DBNAME=${OPENVIDU_COTURN_REDIS_DATABASE}
       - COTURN_REDIS_PASSWORD=${OPENVIDU_COTURN_REDIS_PASSWORD}
       - COTURN_REDIS_IP=${OPENVIDU_COTURN_REDIS_IP}
       - DOMAIN_OR_PUBLIC_IP=${OPENVIDU_PUBLIC_IP}
       - SERVER_PORT=${OPENVIDU_SERVER_PORT}
       - KMS_STUN_IP=${OPENVIDU_COTURN_IP}
       - KMS_STUN_PORT=3478
       - KMS_URIS=["ws://localhost:8888/kurento", "ws://localhost:8889/kurento"]
       - OPENVIDU_SECRET=${OPENVIDU_API_PASSWORD}
       - OPENVIDU_WEBHOOK=${OPENVIDU_WEBHOOK}
       - OPENVIDU_WEBHOOK_ENDPOINT=${OPENVIDU_WEBHOOK_ENDPOINT}
       - SERVER_SSL_ENABLED=false
     hostname: openvidu.hosted.com
     image: apheleia/openvidu:2.18.0
     network_mode: host
     tmpfs:
       - /run
       - /tmp
       - /var/run
       - /var/tmp
     tty: true
     volumes:
       - /etc/letsencrypt/:/etc/letsencrypt/:ro
   pdns-sql:
     build:
       context: ./docker/pdns-sql/
     container_name: kolab-pdns-sql
     depends_on:
       - mariadb
     hostname: pdns-sql
     image: apheleia/kolab-pdns-sql
     network_mode: host
     tmpfs:
       - /run
       - /tmp
       - /var/run
       - /var/tmp
     tty: true
     volumes:
       - /sys/fs/cgroup:/sys/fs/cgroup:ro
   proxy:
     build:
       context: ./docker/proxy/
     healthcheck:
       interval: 10s
       test: ["CMD-SHELL", "curl -so /dev/null http://localhost/ || exit 1"]
       timeout: 5s
       retries: 30
     container_name: kolab-proxy
     hostname: kanarip.internet-box.ch
     image: kolab-proxy
     network_mode: host
     tmpfs:
       - /run
       - /tmp
       - /var/run
       - /var/tmp
     tty: true
     volumes:
       - ./docker/certs/:/etc/certs/:ro
       - /etc/letsencrypt/:/etc/letsencrypt/:ro
       - /sys/fs/cgroup:/sys/fs/cgroup:ro
   redis:
     build:
       context: ./docker/redis/
     healthcheck:
       interval: 10s
       test: "redis-cli ping || exit 1"
       timeout: 5s
       retries: 30
     container_name: kolab-redis
     hostname: redis
     image: redis
     network_mode: host
     volumes:
       - ./docker/redis/redis.conf:/usr/local/etc/redis/redis.conf:ro
   swoole:
     build:
       context: ./docker/swoole/
     container_name: kolab-swoole
     image: apheleia/swoole:4.6.x
   worker:
     build:
       context: ./docker/worker/
     container_name: kolab-worker
     depends_on:
       - kolab
     hostname: worker
     image: kolab-worker
     network_mode: host
     tmpfs:
       - /run
       - /tmp
       - /var/run
       - /var/tmp
     tty: true
     volumes:
       - ./src:/home/worker/src.orig:ro
       - /sys/fs/cgroup:/sys/fs/cgroup:ro
diff --git a/docker/kolab/utils/100-update-roundcube.sh b/docker/kolab/utils/100-update-roundcube.sh
new file mode 100755
index 00000000..cc3c1be0
--- /dev/null
+++ b/docker/kolab/utils/100-update-roundcube.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+# This is incomplete and clearly not how it's supposed to be done,
+# but it will work for now.
+
+cp -Rf /src/roundcubemail/program /usr/share/roundcubemail/program
+
+pushd /src/roundcubemail-plugins-kolab/plugins
+cp -f calendar/*.js /usr/share/roundcubemail/public_html/assets/plugins/calendar/
+find calendar/ -type f \( -name "*.php" -o -name "*.inc" \) ! -name config.inc.php -exec cp -v {} /usr/share/roundcubemail/plugins/{} \;
+
+find libcalendaring/ -type f \( -name "*.php" -o -name "*.inc" \) ! -name config.inc.php -exec cp -v {} /usr/share/roundcubemail/plugins/{} \;
+cp -f libcalendaring/*.js /usr/share/roundcubemail/public_html/assets/plugins/libcalendaring/
+
+find libkolab/ -type f \( -name "*.php" -o -name "*.inc" \) ! -name config.inc.php -exec cp -v {} /usr/share/roundcubemail/plugins/{} \;
+cp -f libkolab/*.js /usr/share/roundcubemail/public_html/assets/plugins/libkolab/
+popd
+
+systemctl reload httpd
diff --git a/docker/kolab/utils/101-update-pykolab.sh b/docker/kolab/utils/101-update-pykolab.sh
new file mode 100755
index 00000000..3941964e
--- /dev/null
+++ b/docker/kolab/utils/101-update-pykolab.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+
+cp /usr/lib/python2.7/site-packages/pykolab/constants.py /tmp/constants.py
+cp -Rf /src/pykolab/pykolab /usr/lib/python2.7/site-packages/
+cp /tmp/constants.py /usr/lib/python2.7/site-packages/pykolab/constants.py
+
+systemctl restart wallace
+systemctl restart kolabd
diff --git a/docker/kolab/utils/102-enable-xdebug.sh b/docker/kolab/utils/102-enable-xdebug.sh
new file mode 100755
index 00000000..bb381028
--- /dev/null
+++ b/docker/kolab/utils/102-enable-xdebug.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+
+yum -y install php-xdebug
+
+cat << EOF > /etc/php.d/xdebug.ini
+zend_extension=/usr/lib64/php/modules/xdebug.so
+
+# Profiler config for xdebug3
+#xdebug.mode=profile
+#xdebug.output_dir="/tmp/"
+#xdebug.start_with_request=trigger
+
+# Profiler config for xdebug2
+#xdebug.remote_log="/tmp/xdebug.log"
+xdebug.profiler_enable = 0
+# Enable using a XDEBUG_PROFILE GET/POST parameter
+xdebug.profiler_enable_trigger = 1
+xdebug.profiler_output_dir = "/tmp/"
+#xdebug.remote_enable=on
+#xdebug.remote_port=9000
+#xdebug.remote_autostart=0
+#xdebug.remote_connect_back=on
+#xdebug.idekey=editor-xdebug
+EOF
diff --git a/docker/kolab/utils/104-update-syncroton.sh b/docker/kolab/utils/104-update-syncroton.sh
new file mode 100755
index 00000000..56cd3441
--- /dev/null
+++ b/docker/kolab/utils/104-update-syncroton.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+
+pushd /src/syncroton/
+cp -f lib/*.php /usr/share/kolab-syncroton/lib/
+cp -Rf lib/ext/Syncroton /usr/share/kolab-syncroton/lib/ext/Syncroton
+popd
+
+systemctl reload httpd
diff --git a/ext/.gitignore b/ext/.gitignore
new file mode 100644
index 00000000..72e8ffc0
--- /dev/null
+++ b/ext/.gitignore
@@ -0,0 +1 @@
+*
diff --git a/ext/README.md b/ext/README.md
new file mode 100644
index 00000000..64bfda59
--- /dev/null
+++ b/ext/README.md
@@ -0,0 +1,3 @@
+Use this directory to clone external git repositories (roundcubemail, roundcubemail-plugins-kolab, pykolab).
+
+This can then be used for a development setup.