Hi Mark,
there are multiple aspects: CodeWarrior supports a wide range of devices (RS08, S08, ColdFire, ColdFire+, S12Z and Kinetis), while KDS is only for Kinetis: as such, it can be leaner and smaller. The other aspect is: while CodeWarrior is a sold/licensed product, KDS is complimentary, free and unlimited. Yes, it is Eclipse based and has Processor Expert intergrated, so if you know Eclipse/CodeWarrior, things are very similar. Both CodeWarrior (for Kinetis) and KDS use GNU (gcc) as compiler. The biggest difference is the debugger: CodeWarrior uses a proprietary debugger engine, while KDS is using GDB. Like CodeWarrior, it supports P&E and Segger connections, but KDS adds the open source OpenOCD/CMSIS-DAP to the mix. The good news for anyone else using something different than Windows: KDS 1.0beta covers now Windows and Linux, with Mac OS X to follow later this year.
The idea behind it: KDS is free and unlimited, and based on open source tools. With Eclipse + GNU gcc + GNU GDB + OpenOCD/CMSIS-DAP it gives end-to-end open source tools, on the most commen host operating systems, supports for widely used run control solutions (P&E and Segger) and has Processor Expert integrated.
More information: http://www.freescale.com/kds
Regards,
Erich