Firefox 35 is the latest version of the web browser that is made available to all Stable channel users as of January 13, 2015.
All other Firefox channels, that is Beta, Aurora, Nightly and Extended Support Release, are also updated to the next major version which in this case means Beta 36, Aurora 37, Nightly 38 and ESR 31.4.
You can find out which version and channel you are running by typing about:support in the browser's address bar and hitting enter.
The page that opens up displays the information under Application Basics.
