Zwiki is.. a powerful, innovative, user-friendly wiki engine based on the Zope 2 platform. This project has been developed since 1999 by Simon Michael and contributors around the world, powers many Zope and non-Zope-related wikis, and is free software released under the GNU GPL . Please explore the site, and enjoy the software. Your questions, comments, patches and donations are most welcome!
Foswiki is a wiki, so you and your team members can collaborate and edit pages directly in the web browser. For advanced collaboration, Foswiki lets you enter macros (similar to Excel) to automate pages and build entire applications from within your browser.
WIKINDX is a free bibliographic and quotations/notes management and article authoring system designed either for single use (on a variety of operating sytems) or multi-user collaborative use across the internet.
OpenStreetMap is a free editable map of the whole world. It is made by people like you. OpenStreetMap allows you to view, edit and use geographical data in a collaborative way from anywhere on Earth.
Pronounced: [wicked-base]Wikidbase is an idea that - as the name sugests - combines the functionalities of a database system and a wiki web application.