Get Firefox Now

Are you ready to infiltrate society and spread Firefox one sticker at a time? Operation Firefox is currently recruiting agents to place huge 3.5’ Firefox stickers where the world will see them. In addition to worldwide notoriety, you might wind up with a new MacBook Pro or a Nintendo Wii.

Operation Firefox began last summer as a project initiated by the Mozilla Marketing interns. We had seen what the Mozilla community produced before, including the New York Times ad, the Firefox crop circle, and the Firefox Flicks contest, and decided to step up to the challenge and create another opportunity for Mozilla fans to show off their creativity.

This newest campaign puts 3.5 foot Firefox stickers in the hands of our community and looks for creative new ways to share Firefox with the world. Ultimately, our goal is to get 50 great photos of the Firefox logo in situations that promote some of the defining characteristics of the Web browser–performance, security, customization, and community.

The contest is two-tiered: first, we’re putting out a call for the 50 best “placements” for these stickers (due November 9th). Then, the most creative agents will receive a fathead sticker to complete their mission: take a photograph and submit before December 3rd. All 50 photos will be displayed on the Operation Firefox website, but the four best ones will receive a new MacBook Pro or Nintendo Wii.

Do you think you have what it takes to be an Operation Firefox agent? To learn more about the contest and how to participate, visit www.operationfirefox.com.

A lot of people complain about the Firefox “memory leak(s)”. All versions of Firefox no doubt leak memory - it is a common problem with software this complicated. We look to fix the issues where we can. David Baron and others have done a huge amount of excellent work in this area.

What I think many people are talking about however with Firefox 1.5 is not really a memory leak at all. It is in fact a feature.

To improve performance when navigating (studies show that 39% of all page navigations are renavigations to pages visited < 10 pages ago, usually using the back button), Firefox 1.5 implements a Back-Forward cache that retains the rendered document for the last few session history entries. This can be a lot of data. It's a trade-off. What you get out of it is faster performance as you navigate the web.

For those who remain concerned, here’s how the feature works. Firefox has a preference browser.sessionhistory.max_total_viewers which by default is set to -1. When set to this value, Firefox calculates the amount of memory in the system, according to this breakdown:

(reference: nsSHistory.cpp)

No more than 8 pages are ever cached in this fashion, by default. If you set this preference to another value, e.g. 25, 25 pages will be cached. You can set it to 0 to disable the feature, but your page load performance will suffer.

Edit: In the comments, Boris and David pointed out that I misread the code, and that this is a global preference so that there are no more than 8 cached pages for the entire session, not per tab. My initial posting had claimed that it was per-tab. Oops!