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It is created by the WordPress team, free and highly extendable with many a heap of free extensions. There is no specific changes to do with Woffice, it will work fine right out of the box.
You just need to install it, activate it and create your forum pages.
Also, note that there is an integration with BuddyPress that you can enable in the BuddyPress' settings. That will let you create one forum per group.
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