YAGARTO is a cross development environment for the ARM architecture, running on a Windows host. It includes the GNU C/C++ toolchain and the Eclipse IDE.
Good, but the newest version is only available for 64-bit Macs. The 2011-11 version works for 32-bit though. My 2006 1st gen MacBook is still kicking it :)
What happened to Linux support? GNUARM had it. Now GNUARM is gone.