seventeen/ten

Whilst Microchip distribute the free MPLAB IDE for Windows, there are many solutions from the open-source community which can be ported to the Mac platform.Unfortunately the only solution to a complete development environment, from C code authoring to in-circuit debugging, is still only possible on Windows, with MPLAB. However if you don't need (or don't have the hardware required) to debug then you can go a long way with the open-source (or commercial) tools available for the Mac. If you're still keen to get going then read on...

QUICK UPDATE:

Microchip released a new version of their IDE called MPLAB X. This offers full support for Windows, Mac and Linux. It can be downloaded for free and installers for the new IDE and C compilers can be found here.

It seems to only support the most recent programmers/debuggers, i.e. PICkit 3, ICD 3, although I have seen suggestions that some of the newest ICD 2 models are supported.

I have only managed to play with it as an editor/compiler (because of the above) but so far it looks pretty good.