FreeBSD Technologies in New Firefox 3 Browser

Boulder, CO - Mozilla this week released the highly anticipated Firefox 3 browser. The FreeBSD Project congratulates the Mozilla project on a multi-year effort that culminated in a product that is both faster and more secure than its predecessors, with innovative new features. Several important features of the Firefox browser were incorporated from technologies adopted from the FreeBSD project. Technology from the FreeBSD project has a long history of being used inside other open source projects such as Firefox.

One of the FreeBSD technologies used by Firefox 3 is the new memory allocator, "jemalloc'', which was written by FreeBSD developer Jason Evans for the FreeBSD 7 operating system. jemalloc is a fast, efficient memory allocator with excellent performance on multiprocessor machines. Though already a part of the FreeBSD 7 operating system, the Mozilla project has chosen to also incorporate it directly inside the Firefox 3 browser to improve memory performance and reduce memory use on other operating systems with legacy memory allocators.
 
According to the blog of Firefox developer Stuart Parmenter, "Our automated tests on Windows Vista showed a 22% drop in memory usage when we turned jemalloc on." Commenting on the Linux version of the browser, he wrote, "We saw a good performance increase and a drop in memory."

Another FreeBSD technology used by Firefox is the "bsdiff'' binary patch system written by Colin Percival as part of the FreeBSD Update mechanism for updating the FreeBSD operating system. By using bsdiff, Firefox is able to dramatically reduce the size of its software updates, meaning faster downloads for end users. In addition to being used by FreeBSD and Firefox, bsdiff is used by Apple to distribute updates to the OS X operating system.

The FreeBSD operating system is supporting Firefox in other ways, too. FreeBSD was integral in delivering Firefox software into the hands of users through its association with the Internet Systems Consortium (ISC), which operates one of the Mozilla project's primary download mirrors, mozilla.isc.org.

ISC is a long-time supporter of the FreeBSD project, and FreeBSD 7 powers the mirror that withstood a sustained download rate of a gigabit per second, during peak download periods throughout Firefox's world record breaking "Download Day."

"ISC saw four times the normal volume of downloads from the mozilla.isc.org site during Download Day," said Peter Losher, Hosted@ISC Programme manager. "As usual, FreeBSD proved to be a rock-solid platform enabling us to deliver content without incident."