Are there any open source solutions out there for setting up company collaboration sites? I've been checking out Open Atrium (openatrium.com) but it still in its early stages and lacking features.
It doesn't have to be enterprise level as the user base will probably be ~ 30 users.
Open Atrium is pretty polished but I would like to consider other options if there are decent ones out there.
Thanks !
Have you tried mediaWiki, which is used to power wikipedia? I am not sure what your requirements are so it is hard to suggest a specific solution. But mediaWiki is open source, stable and widely used.
I see two major options: Wikis and/or CMS.
In the open source Wiki world, I'd consider XWiki or Foswiki. I've experimented both solutions and they both are great Wiki engines. However, XWiki is currently my preferred Wiki engine. If Java is not an option, check Foswiki.
If you think a CMS/ECM would better suit your needs, have a look at Alfresco (I guess you already checked Drupal as Open Atrium is based on it).
PS: All mentioned solutions are very mature and widely used.