The first minor update to Mozilla Firefox 3 has been released. Firefox 3.0.1 fixes three critical security vulnerabilities, improves stability and resolves a handful of other small bugs.

The security fixes are detailed in the Firefox 3.0.1 section of the Security Advisories for Firefox 3.0 page. Two of the issues — one related to how Firefox handles command-line URLs to open multiple tabs and another allowing remote code execution by overflowing a CSS reference counter — were also present in Firefox 2 and fixed in Tuesday's Firefox 2.0.0.16 release. Security improvements in Firefox 3 mean that it's not vulnerable to some of the Firefox 2 variants of the command-line multiple tab exploit but it can still be compromised by combining the attack with a script injection flaw.

The final flaw only affects Mac OS X and allows an attacker to crash Firefox with a malformed GIF file, potentially gaining the ability to execute arbitrary code on the victim's computer. This vulnerability is not present in Firefox 2.

The non-security fixes include an issue where the phishing and malware database did not update on first launch and a problem that could cause Firefox to not save the security certificate exceptions list properly. A bug that could result in missing output when printing a selection from a page (bug 433373) was resolved and a Linux issue causing Firefox to always start in offline mode when using a PPP connection (bug 424626) was also fixed. The Public Suffix list has also been updated (bug 438585).

The Firefox 3.0.1 Release Notes have more details about the fixes in this minor upgrade. The new version can be downloaded from the Firefox product page or the Firefox 3.0.1 directory on releases.mozilla.org but most Firefox 3 users are expected to get it via the software update feature built in to the browser or their own operating system's update facility.

Mozilla Firefox 2.0.0.16 was released this week. The stability and security update to Firefox 2 fixes two security bugs, which are detailed in the Firefox 2.0.0.16 section of the Security Advisories for Firefox 2.0 page. Both are rated Critical, the highest of the four ratings.

One flaw is related to how Firefox handles command-line URLs to open multiple tabs and allows an attacker to open potentially malicious URLs in Firefox from another application. One variant of this attack exploits the widely-reported Safari carpet-bombing vulnerability but others also exist. Somewhat ironically, the exploit relies on Firefox not being open at the time of the attack.

The other vulnerability allows an attacker to crash and run arbitrary code on a victim's computer by overflowing a CSS object reference counter. The detailed bug reports for both issues are currently access-restricted to avoid assisting attackers but will be fully opened after users have had some time to install Firefox 2.0.0.16.

Although Firefox 3 was released in June and all users are encouraged to upgrade, Firefox 2 will be maintained with security and stability upgrades until mid-December 2008, according to the Mozilla Developer News weblog, which reported on the release of Firefox 2.0.0.16 on Tuesday. Version 2.0.0.16 is the second Firefox 2 update to be released since the launch of Firefox 3 and follows on from Firefox 2.0.0.15, which fixed twelve security issues.

Existing Firefox 2 users will be offered 2.0.0.16 via the browser's built-in software update feature if enabled. It can also be downloaded from the older Firefox releases page or the Firefox 2.0.0.16 directory on releases.mozilla.org, where it is available in over forty localizations for Windows, Mac OS X and Linux. The Firefox 2.0.0.16 Release Notes contain more general information about the upgrade.

The official Mozilla Blog has confirmation that Mozilla Firefox 3 now holds the official Guinness World Record for the largest number of software downloads in twenty-four hours. On Download Day, there were 8,002,530 downloads of Firefox 3 between 6:16pm UTC/GMT on Tuesday 17th June 2008 and 6:16pm UTC/GMT on Wednesday 17th June 2008.

Gareth Deaves, Records Manager for Internet and Technology at Guinness World Records, presented the official Guinness World Record certificate to Mozilla Europe President Tristan Nitot at a ceremony in London on Wednesday 9th July. While this official certificate is held by Mozilla, anyone who contributed to the record attempt can download their own personalized Firefox 3 Download Day certificate from Spread Firefox.

In a weblog post, Gervase Markham explains that the actual Download Day figure should be 8,002,529, as a Guinness World Records representative downloaded Firefox 3 during the twenty-four period, which cannot count as he is an official. Meanwhile, Mary Colvig has posted some details about the behind-the-scenes efforts that went into organizing Download Day and Asa Dotzler has published responses to some criticisms of the Guinness World Record attempt.

The Internet Explorer team at Microsoft sent Mozilla a cake to mark the release of Mozilla Firefox 3. Mozilla Corporation employee Al Billings, who used to be a project manager for the IE team, posted some photographs of the cake, which features a large Internet Explorer 'e' logo and the message, "Congratulations on Shipping! Love, The IE Team".

This isn't the first cake Mozilla has received from Redmond: in 2006, the IE team sent another cake to congratulate Mozilla on the release of Firefox 2. Mozilla Creative Director John Slater took a photograph of the Firefox 3 cake next to the last piece of the Firefox 2 cake, which has apparently been sitting in a freezer for the past twenty months.

Relations between Microsoft and rival browser manufacturers haven't always been so cordial: in 1997 when Internet Explorer 4.0 was released, Microsoft dumped a giant metal IE logo on Netscape's front lawn. Netscape employees responded by tipping over the prop and spray-painting "Netscape Now!" (a slogan used by the browser maker to encourage users to download) on its side. They then placed a statue of Netscape's green Mozilla mascot — described in contemporary reports as being either seven feet (2.1 metres) or twelve feet (3.7 metres) tall — on top of it and adorned it with a placard reading "Netscape 72, Microsoft 18", a reference to the market shares of the two leading browser vendors at the time.

The official Mozilla Blog reports that there were over eight million downloads of Mozilla Firefox 3 in the twenty-four hours after release, despite the widespread server availability problems. The Spread Firefox Download Day 2008 page has an interactive map showing the numbers of downloads in different countries and Mozilla Corporation CEO John Lilly has a weblog post with more statistics from Firefox 3's first twenty-four hours.

Once the exact figure has been determined and verified by Mozilla's own judges and officials from Guinness World Records, Firefox 3 will be declared the holder of the world record for the most software downloads in twenty-four hours (since the record doesn't exist yet, there's no real doubt that it will be awarded to Firefox 3). The Download Day FAQ has more details about the specifics of the record attempt.

The Blog of Metrics, run by the metrics and analytics team at Mozilla, reports that Firefox 3 had a market share of around four percent at the end of Download Day, based on hour-by-hour tracking of Firefox 3's market share by Net Applications (it was around 0.96 percent when Net Applications began tracking). By comparison, it took Firefox 2 a month to reach 3.62 percent.

Mozilla Firefox 3 has been released. Available for Windows, Mac OS X and Linux in 46 different localisations, Firefox 3 is the most major Mozilla browser release since the launch of Firefox 2 in October 2006 and represents the culmination of over three years work (development on Firefox 3 began before even Firefox 1.5 came out). According to the press release announcing Firefox 3, the new version has over 15,000 improvements.

Firefox 3 can be downloaded from the redesigned Firefox product page or the Firefox 3.0 directory on releases.mozilla.org (it's not yet being offered to Firefox 2 users via the software update system). More information can be found in the Firefox 3 Release Notes.

The use of newer technologies means that Firefox 3 has higher system requirements than Firefox 2. In Microsoft land, Windows 95, 98, ME and NT 4.0 are no longer supported. On the Mac side, the minimum OS X version jumps from 10.2 Jaguar to 10.4 Tiger. In both cases, the operating system versions that are no longer supported have long since been abandoned by even Microsoft and Apple.

The Mozilla servers have been experiencing problems due to high demand for Firefox 3. This actually delayed the full release of Firefox 3 by more than an hour. According to a Mozilla Developer News weblog post, Firefox 3 is being downloaded more than 14,000 times a minute.

With the launch of Firefox 3, Mozilla is hoping to set a Guinness World Record for the most downloads in twenty-four hours. The number of downloads so far can be tracked at downloadcounter.sj.mozilla.com. Only full, completed downloads count and users have until 11:16am Pacific Daylight Time on Wednesday (6:16pm UTC/GMT) to make a participating download. The official Mozilla Blog has an entry about the Download Day with more details.

Those who just can't get enough of the Firefox 3 launch are invited to attend a Mozilla Party to celebrate or watch the action live from Mozilla HQ on Air Mozilla.

Read the full article for more details about what's new in Firefox 3.

Mozilla Mac developer Josh Aas has written a weblog post discussing some of the under-the-hood improvements specific to the Mac OS X version of Mozilla Firefox 3.

Josh describes how Firefox 3 has largely switched from Apple's legacy Carbon API (initially created to make it easier for developers to migrate OS 9 applications to OS X) to the more modern Cocoa. He also details how Firefox 3 delivers native-looking Aqua-style form controls in Web pages and explains how this actually has very little to do with the change to Cocoa.

Finally, Josh covers how graphics in Firefox 3 are drawn using Core Graphics (which encompasses the Quartz technologies) and ATSUI instead of the deprecated QuickDraw (which has been around in some form or another since the original Macintosh was launched in 1984). This change was achieved by replacing the Mac-specific graphics code with the cross-platform cairo library, which uses Core Graphics and ATSUI on OS X. Core Graphics can take advantage of hardware acceleration to improve performance.

All the changes Josh discusses were implemented in version 1.9 of the core Gecko rendering engine (rather than being specific to Firefox 3), so they will also find their way into other Mozilla-based applications, such as Mozilla Thunderbird (version 3.0 will be based on Gecko 1.9) and Camino (though Camino has used modern OS X technologies since its inception, it will benefit further from the upgrade to Gecko 1.9 in Camino 2.0).

Josh has also written a post outlining plans for more OS X improvements in Gecko 1.9.1, which is scheduled for completion around the end of this year. Much of the work will focus on continuing to remove Carbon code in favour of Cocoa, which will pave the way towards enabling 64-bit versions of Firefox and other Mozilla applications (64-bit OS X programs cannot use Carbon), though this work is unlikely to be finished in the 1.9.1 timeframe. Other improvements may include support for HTML data on the clipboard and reading proxy settings from the system-wide Network preferences.

Deb Richardson has written a lengthy, screenshot-filled Field Guide to Firefox 3 with information about the new and improved features in Mozilla Firefox 3, which launches on Tuesday.

Topics covered include the Add-ons manager, bookmarks, CSS, support for color profiles, the Downloads window, font and text rendering, browsing history, the <canvas> HTML element, showing non-ASCII characters in the Location bar, malware protection, the Microformats API (for extension developers), password management changes, performance and memory usage improvements, phishing protection, plugins, the Site Identification button, enhanced Location bar autocomplete, tabs, the default theme, audio and video podcast support, integration with Parental Controls on Windows Vista and Web application protocol handlers. Each section of the guide includes links to articles and weblog posts containing more details.

A Simplified Chinese translation of the Field Guide to Firefox 3 is available and Deb has released the Field Guide to Firefox 3 under the Creative Commons Attribution-Share Alike 3.0 license to encourage other translations.

The Mozilla Developer News weblog is carrying an announcement that the final version of Mozilla Firefox 3 will be released on Tuesday 17th June.

"After more than 34 months of active development, and with the contributions of thousands, we're proud to announce that we're ready," the message says. "It is our expectation to ship Firefox 3 this upcoming Tuesday, June 17th."

It should be noted that there is still a small chance that a show-stopper bug could delay the release. However, barring any unforeseen disasters, Firefox fans can now circle next Tuesday in their calendars as Firefox Download Day when millions of users will attempt to set the Guinness World Record for the most software downloads in 24 hours. Anyone planning to host a Mozilla Party on the actual Firefox 3 launch day now also knows which date to target.

The third and final release candidate of Firefox 3 was made available earlier today with a workaround for a Mac OS X bug.

A third release candidate of Mozilla Firefox 3 has been issued with a workaround for a bug introduced in the latest 10.5.3 update of Mac OS X. The problem causes the operating system to hang on shutdown if an application tries to open the VerifiedDownloadPlugin.plugin file, which is a browser plugin included in OS X and accessed by Firefox under certain circumstances. Though the bug is not caused by Mozilla code, the developers have decided to include a workaround in Firefox 3 to prevent users from being exposed to the hang. The problem has also been reported to Apple.

Firefox 3 Release Candidate 3 can be downloaded from the Firefox release candidates download page or the 3.0rc3 directory of releases.mozilla.org. Existing Firefox 3 release candidate testers can also upgrade using the built-in software update feature of the browser. Note that although RC3 builds are available for Windows and Linux, they do not contain any changes from RC2; only the OS X builds are different.

The Firefox 3 Release Candidate 3 Release Notes contain general information about the improvements in Firefox 3. Technical information about the specific OS X 10.5.3 VerifiedDownloadPlugin.plugin issue can be found in bug 436575.

Interested community members are invited to take part in a Firefox 3 RC3 Testday on Friday. The virtual event will take place in the #testday irc.mozilla.org channel on Friday 11th June between 7:00am and 5:00pm Pacific Daylight Time (2:00pm Friday to midnight Saturday UTC/GMT).

As well as Firefox 3, the VerifiedDownloadPlugin.plugin bug introduced by OS X 10.5.3 also affects Firefox 2. For this reason, the workaround has been checked in to the 1.8 branch and will presumably be included in the next minor update of Firefox 2. Other Mozilla-based applications may also be impacted.

Update: The Firefox 3 RC3 Testday will take place on Friday 13th June, not the non-existent Friday 11th June as stated above.

Mike Beltzner has created a screencast introducing some of the new features in the forthcoming Mozilla Firefox 3. The overview, which is in Adobe Flash SWF format and lasts three minutes and forty-six seconds, covers the new Location bar autocomplete functionality (dubbed the "awesomebar" by its fans), one-click bookmarking using the new star button, bookmark tags, the site identity button (personified by Larry the passport officer), malware protection, improvements to the file download user interface and the built-in Add-ons browser.

Mozilla is aiming for a new Guinness World Record for the most downloads in 24 hours. Spread Firefox is running a drive to download Firefox 3 on launch day.

At this time, over 800,000 people have pledged to download Firefox 3 to help set the Guinness World Record.