Earlier today, Mozilla uploaded new nightly builds of its web standards-based mobile operating system, Firefox OS. You can download and try them for yourself, but be warned: this isn't your garden variety application install. You'll first have to install one of the nightlies from Mozilla's website, then use the command line to download and configure Gaia, the HTML 5 UI layer. Don't worry if we've already lost you — these builds are mostly intended to be used as a tool for developers to test their webapps against. If you're curious about what makes Firefox OS tick or just eager to give the new OS a try, a blog post by Mozilla's Tony Chung has some brief instructions on how to get started.