@OlgaTPark's Intel TenFourFox fork is a bit unusual in that it is based on 45.9 (yes, back before the FPR releases began), so it is missing later updates in the FPR series. On the other hand, it does support Tiger (mainline Intel TenFourFox requires at least 10.5), it additionally supports several features not supported by TenFourFox, i.e., by enabling Mozilla features in some of its operating system-specific flavours that are disabled in TenFourFox for reasons of Tiger compatibility, and also includes support for H.264 video with ffmpeg.
H.264 video has been a perennial request which I've repeatedly nixed for reasons of the MPEG LA threatening to remove and purée the genitals of those who would use its patents without a license, and more to the point using ffmpeg in Firefox and TenFourFox probably would have violated the spirit, if not the letter, of the Mozilla Public License. Currently, mainline Firefox implements H.264 using operating system support and the Cisco decoder as an external plugin component. Olga's scheme does much the same thing using a separate component called the FFmpeg Enabler, so it should be possible to implement the glue code in mainline TenFourFox, "allowing" the standalone, separately-distributed enabler to patch in the library and thus sidestepping at least the Mozilla licensing issue. The provided library is a fat dylib with PowerPC and Intel support and the support glue is straightforward enough that I may put experimental support for this mechanism in FPR14.
(Long-time readers will wonder why there is MP3 decoding built into TenFourFox, using minimp3 which itself borrows code from ffmpeg, if I have these objections. There are three simple reasons: MP3 patents have expired, it was easy to do, and I'm a big throbbing hypocrite. One other piece of "OlgaFox" that I'll backport either for FPR13 final or FPR14 is a correctness fix for our MP3 decoder which apparently doesn't trip up PowerPC, but would be good for Intel users.)
Ordinarily I don't like forks using the same name, even if I'm no longer maintaining the code, so that I can avoid receiving spurious support requests or bug reports on code I didn't write. For example, I asked the Oysttyer project to change names from TTYtter after I had ceased maintaining it so that it was clearly recognized they were out on their own, and they graciously did. In this case, though it might be slightly confusing, I haven't requested my usual policy because it is clearly and (better be) widely known that no Intel version of TenFourFox, no matter what version or what features, is supported by me.
On the other hand, if someone used Olga's code as a basis for, say, a 10.5-specific PowerPC fork of TenFourFox enabling features supported in that OS (a la the dearly departed AuroraFox), I would have to insist that the name be changed so we don't get people on Tenderapp with problem reports about it. Fortunately, Olga's release uses the names TenFiveFox and TenSixFox for those operating system-specific versions, and I strongly encourage anyone who wants to do such a Leopard-specific port to follow suit.
Releases can be downloaded from Github, and as always, there is no support and no promises of updates. Do not send support questions about this or any Intel build of TenFourFox to Tenderapp.