Mozilla has announced a new alpha release of its Fennec mobile browser for Android and the Nokia N900. Fennec offers support for add-ons and has tight integration with Firefox Sync, a browser synchronization service that was formerly called Weave.

The support for Firefox Sync is arguably Fennec's killer feature, especially because Mozilla is planing to include the synchronization features out-of-the-box in Firefox 4. Users will be able to have access to the their bookmarks, browsing history, and tabs across all of their computers and supported mobile devices.

We tested the latest Fennec alpha build on a Nexus One running Android 2.2. The browser has matured a bit since our last test earlier this year, but its performance still doesn't match that of Android's own native WebKit-based browser. Scrolling remains sluggish at times, particularly when pages are still loading. Starting up the browser takes too long and it still has issues properly preserving state between uses.

On a positive note, Fennec's large 30MB install footprint on Android is a bit less troubling now because a chunk of the program can be trivially moved from internal storage to an SD card. This capability, which is accessible from the Android application manager, was made possible by some new functionality that was introduced in Android 2.2.

The Android port of Fennec is still obviously at a relatively early stage of development, but it shows some promise despite its weaknesses. We're a bit skeptical that Mozilla can truly close the performance gap on Android between Fennec and Google's native browser, but that ultimately might not matter. The synchronization features and powerful add-on framework might be enough to attract users to Fennec despite the browser's other limitations.