Just like the newly released IE9, Firefox 4 will also come with "Do Not Track" feature to let users to notify ad companies and websites that they don't want their online history to be tracked. This functionality of IE9 and Firefox 4 could force to include similar features in its Web browser Chrome.
Firefox 4 is not available yet, but eager web surfers have already found it on Mozilla public servers. However, the Mozilla Foundation is urging people not to download the new browser before the company releases it officially.
Separately, Mozilla said that it was surprised at Microsoft's decision to abandon the Windows XP operating system in its new IE9 Web browser.
Download: Mozilla firefox 4 RC(Release Candidate)