Hi AureliaCH,
As far as I know, the latest is the following link and the following description is from it.
Users can upload, download, edit, and coauthor Office for Mac 2011 documents that are located on a SharePoint site. With Office for Mac 2011, teams, especially those in a mixed environment of
Windows-based and Mac computers, can stay connected and productive, and work collaboratively on documents.
http://mac2.microsoft.com/help/office/14/en-us/admin/item/36ae43a9-5dd3-49ab-a304-ca4d5feb66ee?category=a1c9fe4e-7250-458f-8e3b-d102c6bb8c39
Thanks,
Jack