Appcelerator, a company whose main product is a cross-platform desktop and mobile toolkit called Titanium, has acquired Aptana, whose Aptana Studio 2 is probably the best IDE for JavaScript application development, and which also supports Ruby on Rails, PHP, Python, and Adobe AIR.

It makes sense, in that Titanium uses JavaScript as the primary language for the application logic and UI.

Appcelerator is already doing well from the current surge of interest in mobile apps, offering an obvious solution to developers endeavouring to support both Apple iOS and Google Android with a single code base. Aptana looks a good acquisition; but the news may not be so welcome to those who rely on Aptana Studio for Adobe AIR; I imagine Appcelerator may see this as a competing platform. Then again, most AIR developers use the Flash IDE or Flash Builder so it is unlikely to have a huge impact even if AIR support is dropped (I do not know what the plans are in this respect).

The server-side technologies like PHP and Ruby are a better fit, since many mobile apps have a server component.

Update: in the webcast about the acquisition, Appcelerator CEO Jeff Haynie said “There’s quite a few questions around Aptana as it relates to Adobe and ColdFusion; I don’t think we can say anything about that.”

The company is expecting to release a joint Aptana Studio/Appcelerator Titanium beta in March 2011. The initial release will not include a visual designer, though this is planned for some future release.