This BIMserver project uses a number of different open source licenses to release source code. The core of BIMserver, including the main plugins are licensed under GNU Affero GPL v3. Some other parts are released under the GNU GPL v3 or (for libraries) the LGPL v3 license. The BIMserver software makes use of several other open source projects like BerkeleyDB, IfcOpenShell, EMF, Jetty, osExpress, SceneJS, CityGML4J, and many, many others. Please beware that these individual projects preserve their respective licenses.
More information can be found on http://www.bimserver.org/license/
The sourcecode is hosted on the Github page of the open source BIM collective.