Snow Owl® is a terminology server and a collaborative terminology authoring platform. The authoring platform maintains terminology artifacts developed by a team and supported by business workflows that are driven by external task management systems like Bugzilla and JIRA. With its modular design, the server can maintain multiple terminologies where new terminologies can be plugged-in to the platform. The functionality of Snow Owl is exposed via a REST API.

Getting Started

These instructions will get Snow Owl up and running on your local machine for development and testing purposes. See deployment for notes on how to deploy Snow Owl on a live system.


From version 5.1.0, Snow Owl requires Java 8 update 102 or later.

Snow Owl is an Equinox-OSGi based server (using either Virgo or standalone OSGi). To develop plug-ins for Snow Owl you need to use Eclipse as IDE:

Required Eclipse plug-ins (install the listed features):

Note: you may have to untick the Show only the latest versions of the available software checkbox to get older versions of a feature. Please use the exact version specified below, not the latest point release.

Eclipse Preferences

Make sure you have the following preferences enabled/disabled.

  • Plug-in development API baseline errors is set to Ignored (Preferences > Plug-in Development > API Baselines)

  • The Plugin execution not covered by lifecycle configuration: org.apache.maven.plugins:maven-clean-plugin:2.5:clean type of errors can be ignored or changed to Warnings in Preferences->Maven->Errors/Warnings.

  • Set the workspace encoding to UTF-8 (Preferences->General->Workspace)

  • Set the line endings to Unix style (Preferences->General->Workspace)

Git configuration

  • Make sure the Git line endings are set to input (Preferences->Team->Git->Configuration - add key if missing core.autocrlf = input)

Target platform

  1. Create a prefetched target platform and copy the contents of the target_platform_<version> directory under <eclipse_home>/target_platform.

  2. (Re)Open Eclipse and find the project

  3. Open the file:

  4. Click on Set as Target platform

Run from development environment

  1. Find com.b2international.snowowl.server.update project

  2. Open so_server.product file, click on Launch an Eclipse application and terminate it

  3. Open Run Configurations and find the launch config so_server.product

  4. Open Arguments tab

    • Add -Djetty.home.bundle=org.eclipse.jetty.osgi.boot to the end of VM arguments

  5. Open Plug-ins tab

    1. Add org.eclipse.jetty.osgi.boot bundle (set Auto-Start to true, and Start Level to 5)

    2. Click on Add required bundles

    3. Remove org.eclipse.equinox.http.jetty, org.eclipse.jetty.annotations, all *jsp* and *jasper* bundles

    4. Set the API bundles to start automatically (, by setting Auto-Start to true, and Start Level to 5.

    5. Add the com.sun.el bundle and remove the org.apache.el bundle if necessary

  6. Run and point your browser to http://localhost:8080/snowowl/snomed-ct/v2/

  7. By default Snow Owl will use an empty embedded H2 database. To use MySQL, you have to configure the database in the snowowl_config.yml configuration file (or copy an existing MySQL or H2 configuration file located in the releng/com.b2international.snowowl.server.update/assembly/mysql or h2 directory to <eclipse_home>/target_platform).


Snow Owl uses Maven for its build system.

In order to create a distribution, simply run the mvn clean package -Pdependencies -Psite -Pdist command in the cloned directory.

To run the test cases, simply run:

mvn clean verify -Pdependencies -Psite -Pdist

The distribution package can be found in the releng/distribution/target folder, when the build completes.

Additional Build Improvements

Here are few tips to improve the quality of the default build process.


We highly recommend to install a local artifact repository (Nexus OSS is supported), so the build can deploy and reuse (in downstream projects) Maven and p2 artifacts.

  1. Download and install Nexus OSS or Professional (

  2. Install Nexus Unzip Plugin to easily reference p2 repositories deployed as zip:

  3. Define the nexus.url parameter in the settings.xml file under .m2 folder on your build server (use the settings.xml in the root of this repository as template).

  4. Define a deployment user in Nexus, and reference it in the .m2/settings.xml file.

  5. Use mvn clean deploy instead of mvn clean verify when you execute the process.

  6. Optional: deploy only if build succeeds (requires a Jenkins CI job with post build step to deploy artifacts to Nexus

Prefetched target platform

The -Pdependencies profile includes all required third party repositories and modules as part of the build process using Tycho's p2 and Maven dependency resolution capabilities. While this should be enough to run the process, in production builds we recommend using a prefetched target platform, as it will ensure consistent third party versions and reduces the execution time significantly.

  1. Create the target platform update site, run mvn clean verify -Pdependencies -Ptarget_site from the releng folder

  2. Navigate to folder

  3. Copy the target_platform_<version> folder to a webserver, or use Nexus to serve the site as unzipped p2 (requires Nexus OSS with Unzip Plugin installed, see previous section)

  4. Define an http URL as target.platform.url parameter in the global Maven .m2/settings.xml file

  5. Run Snow Owl maven process with mvn clean verify -Ptp_dependencies -Psite -Pdist (NOTE: the tp_dependencies profile will use the prefetched local p2 repository instead of querying all remote sites)


Please refer to the installation guide. Prerequisites are detailed in the software requirements document. Then see the configuration guide to configure for your particular installation.

The SNOMED CT extension management guide provides details for managing multiple SNOMED extensions on a single terminology server.


See the administration guide. You may find the quick references for console commands and the administration REST API helpful.


Please see for details.


Our releases use semantic versioning. You can find a chronologically ordered list of notable changes in


This project is licensed under the Apache 2.0 License. See LICENSE for details and refer to NOTICE for additional licencing notes and uses of third-party components.


In March 2015, SNOMED International generously licensed the Snow Owl Terminology Server components supporting SNOMED CT. They subsequently made the licensed code available to their members and the global community under an open-source license.

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