Rainbird on 13 April 2010
The way I'm interpreting it, Microsoft requires developers to have an independant publisher before they will allow their game on XBLA, and since the game is out on Linux and Mac, Microsoft won't do the publishing (which I assume is a better deal for the developers than getting someone like EA, THQ or whatever. Otherwise I don't understand why we have this situation to begin with).
On PSN and WiiWare, an independant publisher is not required, so these guys can publish it themselves and only pay the licensing to the platformholder, and not any publishing fees.
This is entirely what I have made of it so far, I don't know how factual that it is.
