Question

Is there an open source alternative to SharePoint?

I’d like something that gives the same hierarchical structure and portlet-based design of SharePoint, but is open in source. Web based administration and customization is also a plus.

Answer 1

I depends on what you need.
Is it used as content managment system ? There is plenty open source CMS, as stated before.

Is it used as collaboration tool ? Then one of the follwing things may do the trick:

• eGroupWare: Already available on many hosters, project manager, Infolog for Notes, Tasks, ToDos, and more tools.
• Collanos Workspace: Java on Mac, Win or Linux, chats, discussions incorporated
• OpenGoo: PHP, tasks, calendar, contacts, weblinks, internal messages, with editor for text-documents and presentations (!)
• eyeOS pushes it one level further. It’s like a desktop in your browser, including internal drag and drop etc. It incorporates beforementioned OpenGoo, can be enhanced by a multitude of ‘programs’ to be downloaded separately. Sole problem: eyeOS needs full read/write permission on the files, which is often a problem with hosters.

edit: I just found something else and thought it would be worth adding here: O3Spaces (see german article) sees itself as alternative to Sharepoint and has just been released in a new version.