eXo|platform
Seems quite good solution for within a company or institution.
Pros
-
Free community version [eXo Tribe](https://community.exoplatform.com/portal/intranet/) -
extensible with add-ons
-
public/private channels to hold discussion
-
integration with other standard solutions like online docs, dbs, etc. (enterprise edition)
Cons
-
set up accounts to everyone
-
not federated, if two universities are using instances of it - they cannot use same login/password to collaborate with other university.