Our MobileFrontend extension, which is currently deployed on Wikimedia sites, uses WURFL to detect the mobile devices it targets. However, I recently became aware the version of the WURFL data files we use has a rather restrictive license.
http://tech.groups.yahoo.com/group/wmlprogramming/message/34311
The license seems to suggest we are not even supposed to redistribute verbatim copies or install the data files on multiple servers rather than only making "[...] one copy [...]", if not merely fail to grant such permission. Currently, the files are in our Subversion repository and are going to end up in Git soon.
I am not a lawyer, and I realize this is probably a matter for the Wikimedia Foundation to handle, albeit one of urgent importance to us. If I am not mistaken, proper removal of infringing material from Git repositories is somewhat painful in that it causes all child SHA-1 hashes to change, so I feel resolution of the above licensing concern blocks Git migration of at least the MobileFrontend extension.