With Firefox 3.5 release coming near, Mozilla has already started working on Firefox’s next version codenamed Namoroka that is scheduled to launch in mid 2010. The pre-alpha builds are already out for Windows, Mac, and Linux. To keep day-to-day tab on the nightly builds, follow the link given at the bottom.
The release is being called Firefox 3.6, but should not be considered as a final name since it might later be called as Firefox.Next due to vast improvements and new features. To learn what’s new in Firefox 3.6, visit the Mozilla Links blog.
Download Firefox Nightly Builds