Firefox user’s don’t wait for a long time to get newest update of Firefox 4 Beta. Mozilla has released Firefox 4 Beta 11 not more then 2 weeks after they released Firefox 4 Beta 10. Mozilla is planning to release at least one more beta and then a round of release candidates before Firefox 4 is finalized later this year. It means we don’t wait for a long time again to get Firefox 4 Final version. This software include “Do not track feature” function, re-enable WebGL on Linux version, and do not automatic offline mode when you open Firefox without internet connection.
“Do not track feature” is a feature to tell websites that the user wishes to opt out of behavioral tracking. Websites have to interpret the header correctly and advertisers need to abide by it for it to have a positive effect. You can active or deactivate from Tools > Options > Advanced. It is not clear why it has been moved to the advanced tab and not the privacy tab where it feels more natural.
You can check all new feature here
If you use Firefox 4 Beta older version then your software will automatic update (remember to set automatic update on Options > Advance > Update) to Firefox 4 Beta 11. Alternative you can download manually form Firefox website.