Liferay Social Office

Liferay Social Office is a social collaboration solution for the enterprise that streamlines communication, saves time, builds group cohesion and raises productivity.
You can work on documents right from within Social Office or open and save them from Microsoft Office®.

Social Office takes care of version control and check-in/check-out. Users can add comments, ratings, and tags.
Social Office brings collaboration into your daily routine without requiring extra steps.