CooCox Yesterday I posted some links to the CooCox system. If you check their forums someone has done some work so that this kit can be used with their system and the "Standard" EABI ARM cross compiler. The older Discovery Kit now works directly.
I have successfully used IAR, CooCox and EABI compiler under cygwin and MinGw -- lots of choice.
So if you do not have the bankroll for IAR -- which is worth every dime -- try the other routes.