How can I install the X11 version of Firefox on Snow Leopard? (Preferably without MacPorts or Fink?)
Firefox requires a Window library to be linked with e.g. QT, Gnome and several other C libraries. Thus to build it will need a lot of other code so I think using Homebrew/Macports/Fink would save time.

If you want any other X11 apps then Homebrew/Macports/Fink is likely to be the easiest way to get them.

Also as per @Nathan G. I have found installing Macports not to be difficult.