Compiling Firefox for modern-ish (Pentium 4 and newer) CPUs is relatively common on Linux, and presumably on Mac OS X also, but not for Windows. On Windows, Firefox assumes you have a first-generation Pentium CPU, since that’s the slowest CPU that will boot Windows XP.
Enter Pale Moon.Pale Moon is compiled to use the instruction set in newer Pentium and Athlon 64 CPUs. In layman’s terms, this results in about a 25% increase in performance, which is significant.
Also significant is that the current version is based on 3.6.3 of Firefox, before Firefox broke Farmville, people started laying eggs, and they started breaking Firefox to keep Farmville working.
I couldn’t care less about Farmville and other stupid Facebook games; I just want Google Maps to be fast.
And in my quick tests, Pale Moon is fast. It loads faster than the standard Firefox build. It renders complex pages like Google Maps faster.
I’m not ready to make it my default browser yet, but so far I like what I see. It at least narrows the performance gap with Chrome, while retaining the user interface and keyboard shortcuts I’ve been using since those pre-release versions of Netscape I was using in 1994.
Experimental, optimized Firefox builds have come and gone over the years. Hopefully this one sticks around a while.