Mozilla, who still plans to release Firefox 3.5 by the end of the month, took one step closer to that goal on Friday by finally making available the first Firefox 3.5 Release Candidate (RC). Prior to Friday, lingering bugs had forced Mozilla to delay the RC rollout on more than one occasion.

According to Mozilla, Firefox 3.5 RC sports improved tools for controlling private data, better performance and stability thanks to the new Tracemonkey JavaScript engine, support for native JSON and web worker threads, improvements to the Gecko layout engine for faster content rendering, and more.

If you've already installed Firefox 3.5 Beta 4, you should receive an offer to update to the RC automatically. If not, try using the "Check for Updates" option under the "Help" menu.