Mozilla has announced that June 17 is the official date of the much-anticipated Firefox 3 release. Developers and open source software enthusiasts are planning parties all over the world to celebrate the occasion. I'll be covering the release from Mozilla headquarters in Mountain View at the official Camp Firefox event.

Mozilla is encouraging users to participate, too, by helping the Firefox team set the record for the most software downloaded in 24 hours. The total number of unique downloads that take place on release day will be submitted for potential inclusion in the Guinness World Records. Over a million users have already signed up to pledge their support.

Many readers have asked about the status of Firefox 3 add-on compatibility and some have indicated that they won't be ready to upgrade until their favorite add-ons are supported. Mozilla Product Manager Alex Polvi has written a brief overview that explains the current status of the most popular add-ons. Some of my favorites, like Greasemonkey, Firebug, and Stylish are now all compatible with Firefox 3.

Unfortunately, Google Browser Sync is being discontinued and will no longer be supported. Google recommends that users adopt Mozilla Weave or Foxmarks.

Mozilla's add-on team has been hard at work getting a new version of the add-on web site ready in time for the release. The new site includes a theme browser that displays thumbnails and a new advanced search system, as well as numerous improvements for developers.

Planning is already in progress for Firefox 3.1, which is codenamed Shiretoko. Although still in the early stages of planning, the schedule indicates that alpha releases could be available as early as July. Prominent user interface features planned for the 3.1 release include tab previews and tag auto-completion. Developers also plan to add several new features to Firefox's Gecko rendering engine such as the HTML 5 video element and CSS text shadows.

We have closely followed Firefox 3 development since the earliest prereleases in 2006. Our extensive testing has revealed that Firefox 3 delivers significant improvements to resource efficiency and ease of use in addition to countless feature enhancements. For more details, check out our coverage of the prereleases: (a1 a5 a6 a7 a8 b1 b2 b3 b4 b5 rc1).