I prefer http://palemoon.org They offer a 64bit version.
PaleMoon is even more outdated, it's an old Firefox ESR.
FALSE
Pale Moon has been on a divergent path with its own code for a long time already. It was a rebuild in 2009, yes. It was a rebuild with minor changes in the Firefox 4.0 era, yes. But we've come a very long way since then with an increasing amount of different code being carried over each time it was re-based on later Firefox code. It's a true fork now and has been employing rapid development (as opposed to rapid release) to solidify this independent direction with its own focus and attempt at keeping the browser sane, lean, and offering users choice and stability.
At the same time, Pale Moon's focus on security and evolving networking standards has added features and kept pace with those developments in other browsers, by e.g. adding TLS 1.1/1.2 support a while back, by offering OCSP-stapling, by keeping a close eye on encryption and the browser's security by continuing to port or re-implement security fixes that apply to Pale Moon as a browser. It is neither old nor outdated, it is not a "rebuild" and it does not use obsolete technologies or have security holes.