This isn't official, but as I understand it, there are two main funds, the YAS general fund, and the Perl development grant fund. The latter is administered by the Perl Foundation, which is a part of YAS. From that one come the grants which provide the recipents with salaries and travel expenses. (The YAS general fund also pays for the Monastery.)
I got this from the YAS front page and the Perl foundation front page by scanning down the news items. Someone please correct any misunderstandings on my part.