Companies Selling Microcontroller Kits?

An anonymous reader asks: "I'm in college working on an electrical engineering degree, and I've had a few labs so far involving microcontroller setups. I'd now like to start doing some microcontroller projects of my own devising, so I'll need a programmer, the development software, and the MCUs themselves. The problem is that I don't have a wide experience with the different companies selling this sort of equipment. I know about the BASIC Stamps and the PIC offerings, but what other architectures are there? Both of the MCUs I've named have development tools, but they're for Windows. Are there any companies out there that supply their tools for BSD/Linux? What open source projects are there working on this (I've found gputiles). As always, free (as in beer) is good for us college students. :-)"