Latest version doesn't seem to work with MacOS but 2.3.1 does.
Installed with MacOS 10.5.8, Eclipse 3.6 and a new tool chain. Eclipse recognizes the existence of the AVR Plugin, but nothing shows in the new project dialog. I'm sure I'd love to work with this - if I could get it to work!
Takes a bit of learning, and on my old computer, a bit slow...but marvellous once you get the hang of it.
Plugin seemed not to work with the avr make.exe under Windows 8.1 (Windows 8 works). Tested with Juno + Kepler + Kepler-32Bit. An other make.exe (from Sourcery_CodeBench_Lite_for_ARM_EABI) fixed it. Armin