Stephen Shankland/CNET

Just as Apple finished up OS X 10.8, aka Mountain Lion, Google said yesterday that its Web browser will stop supporting OS X 10.5, aka Leopard.

Leopard debuted in 2007 after a long gestation period. Apple's OS updates arrive more frequently these days -- roughly annually -- and Chrome comes even more frequently with a six-week update cycle.

"Please note, on Mac we now require 10.6 or higher, and this release will not be available if you are on 10.5 or lower," said Chrome team member Jason Kersey in a blog post yesterday about Chrome 22, which just entered testing on the developer channel. That version should become the mainstream, stable version of Chrome in about three months.

Chrome has become an "exceptionally profitable" product for Google, driving search traffic and thereby generating ad revenue for the company. It got its start on personal computers, but Google has just released Chrome for iOS alongside the Android version of the browser.

Google also announced yesterday the beta version of Chrome 21 with two significant features for letting Web apps better match what native apps can do.

First is support for the getUserMedia interface, which lets programmers tap into a computer's camera and microphone. That's useful for creating Web apps that use videoconferencing and audio chat, or for signing up with a new online service that can take a snapshot for a profile picture.

Second is support for the Gamepad interface, which lets programmers write Web-based games that use videogame controllers.

Opera Software and Mozilla also have been pushing for development and adoption of these interfaces to device hardware. Such tasks typically have been available to programmers before who used Adobe Systems' Flash Player or who wrote native software that use the underlying operating system.

The browser developers, though, want Web apps to match what native apps can accomplish. That's important for programmers who want to move beyond the Flash era, but it's essential for Google's Chrome OS and Mozilla's Firefox OS, two projects that use a browser-based operating system that runs only Web apps.