The launch of Firefox 3 saw a record-making number: 8,002,530 people downloaded the latest browser from Mozilla in the 24 hours between 18:16 UTC on June 17, 2008 to 18:16 UTC on June 18, 2008.

The Mozilla team congratulated its community and pointed at its grassroots marketing campaign as the secret to the successful launch. As the browser launched, the first four hours saw a million downloads, which later snowballed to over 8 million over the next 20 hours.

"As the arbiter and recorder of the world's amazing facts, Guinness World Records is pleased to add Mozilla's achievement to our archives," Gareth Deaves, records manager for Guinness World Records, said in a statement. "Mobilizing over 8 million Internet users within 24 hours is an extremely impressive accomplishment and we would like to congratulate the Mozilla community for their hard work and dedication."

Here is an interesting snapshot from Mozilla on how things turned out come Download Day, July 17th:

We exceeded the first day download mark for Firefox 2 of 1.6 million after just five hours of availability for Firefox 3.

Net Applications is already reporting a 300% positive change in Firefox 3 market share worldwide just today.

Over 500 articles about the launch were linked to from Google News

The Firefox 3 launch made the front pages of BBC.co.uk, NYTimes.com, Liberation.fr, laRepubblica.it, Digg, Slashdot, Techcrunch, and Yahoo! News

The completely redesigned Mozilla.com launched in over 25 language versions

New community activity on SpreadFirefox.com has skyrocketed with dozens of new groups and hundreds of new postings

Over 700 community launch parties have been registered on mozillaparty.com

Our congratulations to Team Mozilla! If you downloaded Firefox 3, you can grab a cool certificate from here.