#MediaWiki is awesome; it supports some 300 languages in the many Wikipedias and in the incubator. For several hundred languages, all sign languages, there is no Wikipedia yet. Worse, MediaWiki does not support the SignWriting script that is necessary to write these languages.
There are several technical issues that need to be solved SignWriting is written in lanes; that is, they are written top down and the characters may swerve to the right or to the left. To complicate things even more, the SignWriting script is not included in Unicode. MediaWiki relies on Unicode.
It is however REALLY important to have a Wikipedia for sign languages. SignWriting is effectively a grass roots organisations that emancipates the mother tongues of millions of people who live in every country. Being able to write your language, finding your language on the Internet is something we take for granted. For SignWriting it is a school at a time, a language at a time and get to the inflection point where writing a sign language is obvious and asking for a Wikipedia is just a matter of following the procedure.
I am really happy to blog about the first encyclopaedic article in ASL; it is about Charles-Michel de l'Épée. Épée came to believe that deaf people were capable of language and concluded that they should be able to receive the sacraments and thus avoid going to hell. In a modern variation, it is the SignWriting Foundation that concluded that deaf people can write their language and should have their Unicode so that they can write on the Internet and have their Wikipedias.