How can I extract an .xz archive graphically on Mac OS X 10.4? Recent versions of StuffIt will extract .xz archives, but they will not run on Mac OS X 10.4 Tiger. And using something like Fink, it should be possible to install xz-utils on 10.4, so that .xz archives can be extracted from the Terminal.

But is there any graphical application that will run on Mac OS X 10.4 Tiger, and which will extract .xz files?

It's OK if this application supports extracting .tar.xz archives in a single step, but not necessary, because if it extracts the .tar.xz file to a .tar file, even an older version of StuffIt can extract that.
Not graphically, but this showed up in searches so for those of us who want to do it from the command line using Homebrew: 

$ brew install xz
$ xz -d to-extract.xz