[Andrew Andrianov] has the same itch we do when it comes to the variety of inexpensive dev boards out there. They put hardware in your hands but when it comes to the IDE it tends to be a very mixed bag. Some offer hobbled copies of proprietary software, but in most cases you’re on your own for any kind of open source development environment support. He and a couple of friends are working to change that. What they’ve come up with is Antares: a single build system which can compile code for multiple microcontrollers.
The idea is to make the coding environment agnostic from the compile/burn process. This serves a few purposes; it lets you use the IDE you’re most comfortable with, be it Eclipse or emacs. It also seeks to ease the pain of writing libraries that will work with multiple different chips. So far the package supports several of the usual suspects: AVR, msp430, STM32 ARM chips, as well as AT89,and STC variants of 8051. Other chips can be added as more hands make light work (in other words, roll up your sleeves and help these guys out!). Right now development targets Linux dev platforms but OS X has been shown to work with some patches.
The link above is a rather daunting readme from the Github repo. If you need a better overview before diving in hit up the RC1 announcement on [Andrew's] blog.