Android (2.0 and above): It's a "pre-alpha build", but Firefox Mobile, a.k.a. Fennec, is worth testing out on newer Android phones. It's a pretty neat browser with a lot of potential, as shown in our screen captures.

Maemo 5 Phones: Moving right along from the release candidate, Firefox Mobile has arrived in 1.0 form on phones like the N900 that run Maemo. It's got add-ons, an AwesomeBar, desktop syncing through Weave, and pleny more to recommend it.

Firefox: Mozilla's out with the 1.0 of its Weave project, and it delivers on what it first promised — quiet but complete syncing of bookmarks, passwords, preferences, history and even open tabs. It also heralds the coming of a really cool mobile experience.

Windows Mobile 6: Fennec, Firefox's mobile browser, inches closer to a widespread beta with the release of an alpha tested on an HTC Touch Pro, but available for download on any Windows Mobile 6 device.

Mozilla Labs highlights a very cool feature coming to Fennec, the mobile version of Firefox: Fennec now syncs browser tabs with previously mentioned Weave, so you can easily access any of the pages you were browsing on your desktop installation of Firefox from your mobile browser. Handy!

Firefox's mobile browser, Fennec, is available in "milestone" (read: very alpha) downloads for HTC Touch Pro phones, but also most any Windows Mobile phone running at VGA (480x640). Early reports say it's working, if slow. As the Mozilla team itself notes, this release has plug-ins disabled, features no soft keyboard input, doesn't allow for program or add-on updating, and a few other "punts" made to get a working release out. Still, if you want to test out Fennec's unique navigation and mobile browsing helpers and you've got a Windows Mobile phone, it could be worth a try—even if web site loading is not exactly snappy at this point. Fennec is a free download, built for the HTC Touch Pro but capable of running on Windows Mobile phones. A direct CAB link can be found right under the "Installation" heading in the link below. Fennec Milestone Release for Windows Mobile

All platforms (Mac/Windows/Linux): You caught a glimpse of the new Mobile Firefox alpha running on a Windows Mobile device last week, but today you can check out the alpha from the comfort of your desktop. Codenamed Fennec, the Mobile Firefox alpha 1 build gives you a neat look at what's to come on your smartphone and other handheld devices from Mozilla. As the welcome screen instructs, click and drag right to see tabs, and click and drag left to tinker with the software's controls. Fennec is only alpha, and it does show, but it's a promising look at Firefox's take on mobile browsing.

Fennec M9 (user experience alpha) for Maemo release notes