What is open source?
A definition for open source.

Why use open source?
Think Open proposes why you should consider using open source technology.

A Blueprint for Managing Documents
Article at Byte.com that discusses the features of a good Electronic Document Management System.

WebDAV.org
A site produced for the WebDAV community as a central resource for documentation, specifications, software, mailing lists, and other useful items.

OpenUsability.org
Website of OpenUsability.org - a project that brings open source developers and usability experts together.

Opensource.org
A site containing open source resources, including a description of open source licenses.

Project/Open
Website of an open source based project - Enterprise Resource Management (ERP)

GPL Developer Site