Steam now offers the official release version of Double Action: Boogaloo, the free-to-play shooter inspired by John Woo-style action movies (thanks Ant via Linux Today). This had a preliminary release over the summer, but GamingOnLinux notes the official release came a couple of weeks ago for Windows and Linux. There's also a recent update with the status of the OS X edition and workshop support:

The Double Action team has been eating apples all week and the result is that the OSX version of DA is almost ready. Its bits and bytes are currently loaded into Steam and ready to be processed and downloaded by all of our beautiful players, we just have to do make sure none of the apples have any bugs before the hour of final disbursement (exactly what hour? I dunno, whenever we stop eating them apples.)

In addition we're going to release the OSX version in tandem with the Steam Workshop, which will let anyone build and distribute modifications to the game, some of which may be incorporated back into the official version. All of this will happen perhaps some time this weekend (exactly what day? I dunno, whenever it's done.)

EDIT: Sorry guys, looks like the workshop is going to take longer than we thought, it's coming soon, but not as soon. We'll push forward with the Mac support, but workshop will be in a later update.