Looking at the copyrights in the documentation I guess it's a licensed version of Rowley's CrossWorks? If you like Segger's products then maybe it's worth looking into, but otherwise it's hard to get excited about yet another ARM IDE.
Ah, that's unfortunate. The worst part of CrossWorks is the IDE.
I develop primarily on MacOS, and am always interested in something "good" that runs on the Mac.
For now, Eclipse and Sublime Text+make seem to be the only true options. An IDE doesn't provide a whole lot of value, but a visual debugger can be useful. And "go to declaration" etc is helpful when integrating unfamiliar libraries/headers.
Oh well.