Currently the math extension ships with MediaWiki core in the math/ directory. (I'm guessing this is because of historical easons?) However, this is unlike every other extension, which goes into extensions/.
Is there some particularly good reason why math needs to be available on every MediaWiki wiki? If not, could it be moved to extensions/ ?
Of course, I understand that this may be too hard to fix now, but the question might as well be asked.