O3Spaces for Open Office

O3Spaces is an open-source solution that integrates easily to multiple users who are using Open Office providing a common workspace like Microsoft Office Share Point. With an interface very like Web 2.0, O3Spaces documentary works as a manager that lets you share documents, perform version control over them, have a common calendar and exchanging comments and views among members of a working group.In addition to Open Office, it is also compatible with Microsoft Office and Star Office.
There are professional versions for payment, but can be used for free version for the community.The Community Edition enables teams and work groups of up to 10 people to collaborate and share their documents.[source]