Firefox 3.1, codenamed Shiretoko, has reached its first milestone, Alpha 1 pretty much on track for a targeted final release late this year, despite a short delay due to a nasty crash bug with Java on Mac OS X.
Perhaps the most notable improvement with this release is an option to restrict the location bar autocomplete suggestions to either history, tags or bookmarks only as well as an option to tell Firefox to search just for page titles or addresses when looking for a match.
To restrict to history, bookmarks or tags only, enter ^, * or + respectively somewhere between your terms. To include titles or addresses only, you enter # or @, and you can combine them with the previous operators to refine your suggestions.
New advanced settings (accessible entering about:config in the location bar) let you customize all the default characters and set your own character or group of characters to apply restrictions.
Even further, you can set any of the related preferences (browser.urlbar.restrict.history, browser.urlbar.restrict.bookmark, browser.urlbar.restrict.tag, browser.urlbar.match.title, browser.urlbar.match.url) to blank values to apply the restrictions by default (without entering any special character).
This location bar restrictions were considered for Firefox 3 but the performance hit along with time constraints had it postponed for the next iteration. It’s still to be decided if there will be any user interface (possibly in Options(Preferences)/Privacy) to make these options discoverable.
For more details you can check this Edward Lee’s post on the matter. He is the developer largely responsible for this implementation.
Another visible enhancement is the new behavior for the Ctrl + Tab hotkey: instead of switching to the next tab to the right as before, it raises a small overlay with tab thumbnails. Since they are ordered with the most recently viewed first, you can press Ctrl + Tab successively to switch between the current and previous tabs, a handy shortcut for accessing a reference page while composing in another.
By default, only three thumbnails are shown but you can customize it by setting browser.ctrlTab.previewsCount (via about:config) to the desired value and restarting Firefox. I found 5 to be a more useful value.
You can disable the feature altogether setting browser.ctrlTab.mostRecentlyUsed to false and get the old Ctrl+Tab behavior. Ctrl + PgUp and Ctrl + PgDown still provide the classic tab navigation.
Alpha 1 gets much better results in the Acid3 test, a benchmark of web standards support that, as opposed to previous acid test versions, not only assesses CSS compliance but also DOM capabilities and performance. As of this release, Shiretoko scores an 84, an 18% gain compared to Firefox 3′s but still behind WebKit nightlies that already score a perfect 100.
There’s still plenty to come including native audio and video support, possibly font download, one click autologin option for sites where a single set of credentials is available, private browsing, cross site AJAX requests (pulled back from Firefox 3 after late changes to the specification), bulk tagging, tag autocomplete, the possibility to enable color management support (introduced with Firefox 3) by default.
Let’s wait and see what gets in by the next milestone, which according to an early schedule draft, should be a first beta sometime in August.
More details Mozilla Developer News.