The Building Information Modelserver (short: BIMserver) enables you to centralize and manage the information of a construction (or other building related) project. The core is based on the open standard IFC. The BIMserver is nót a fileserver, but uses a model-driven architecture approach. This means that IFC data is interpreted by a core-object and stored in an underlying database. The main advantage of this approach is the possibility to query, merge and filter the BIM-model and generate IFC files on the fly.
Due to the multi-user support, multiple people can work on their own part of the model, while the complete model is updated on the fly. Other users can get update notifications when the model (or a part of it) is updated. Furthermore the BIMserver will warn you when other users have changed something in the model while you were editing.
BIMserver.org is the reference implementation of the BIMSie standard API for BIM in the cloud. More info on http://www.nibs.org/?page=bsa_bimsie and http://bimsie.openbimstandards.org/
See a full list of features on http://www.bimserver.org/ Or get community support at http://support.opensourcebim.org/
Licence: GNU Affero General Public License, version 3 (see http://www.gnu.org/licenses/agpl-3.0.html) Beware: this project makes intensive use of several other projects with different licenses. Some plugins and libraries are published under a different license.
An introduction to BIMserver for developers is given in this video: http://www.youtube.com/watch?v=greB5jHi6JQ&hd=1