On Tuesday, without fanfare, Mozilla quietly released the final alpha for its new Firefox 3, codenamed Gran Paradiso. Alpha 6 doesn't add much to Firefox in terms of new features; we expect that to happen with the first betas. As with previous Alphas, most of the tweaks are internal. See our slide show of Alpha 5 to see what changes are currently visible within Firefox 3.
According to the Alpha 6 release notes this version includes: Updated SQLite engine to version 3.3.17; support for site-specific preferences--text size; a new Quit dialog box that resolves termination errors; added permanent 'Restart Firefox' button to Add-Ons Manager; miscellaneous fixes to download manager including correctly displaying large file sizes; various Places fixes; and miscellaneous Gecko 1.9 bug fixes.
It is the latter, the miscellaneous bug fixes within Gecko 1.9, that may affect Web and platform performance. Once again, Mozilla recommends this alpha release only for developers. Mozilla urges current users of Firefox 2 to wait until Firefox 3 is finally released in October or November of this year.