See http://www.thwackety.plus.com/owiki/

At the time of writting both TWiki and O'Wiki are fairly active OpenSource projects, both under the GPL. In some development areas O'Wiki and TWiki are doing similar things, but there are interesting differences. There is a strong desire to keep a constructive dialogue going between the TWiki and O'Wiki developers. However, this topic has previously seen some strong comment regarding TWiki and O'Wiki. As this said more about some personality differences than about either of these Wikis it has been deleted. If you wish to see this then please see an earlier revision of this topic.

People have asked about compatibility between TWiki and O'Wiki e.g. can I keep my data, but move between the code bases. Currently, there is a high level of compatibility and hence moves are fairly easy, but this may change in the future.

-- JohnTalintyre - 13 Feb 2004