Although it's been nearly 3 years since the last update, DMIDE isn't dead. Jp graciously purchased a membership so I can start blogging about development.
The aim of DMIDE is to be more modern and easy to use than DreamMaker, but a secondary effect is that it runs on many different platforms. You're not restricted to just Windows, which is great since many devs don't mainly run Windows. But don't be fooled, this has nothing to do with DreamSeeker or the likes - so you will still need some sort of virtualization solution to actually run the games outside supported platforms.
There's 5 big parts to DMIDE. The code editor, icon editor, skin editor, map editor, and the general window that glues them all into one and their supporting windows. Neither of these are finished, or even close to. A rewrite and restructure is imminent to support plugins and extensions and reduce the windows' dependencies on each other. There has been a collaboration with Jp, Jon88, and Stephen001 which has rapidly increased development recently. So much thanks to them, and anyone else who has helped. If you've got some knowledge in Python or wxPython/wxWidgets then feel free to lend a hand on the many tasks that need to be done.
DMIDE isn't ready for use yet, and it might contain timebombs so I'm going to refrain from posting a test build. But if you insist on playing with it, you may check it out from the google code svn repo (link in the file tree). Just don't submit any bug reports as it's likely that they come from unfinished parts of different sections. I will post more about the different editors later, for now you can show your support and check out the screenshots on the left.
Thanks to Jon88 for the awesome CSS again!