This is a Leopard-only version of the command-line tool Frotz, which can be used to play text adventures in the Mac OS X Terminal. See the installer information screen for further details.
This program is rather out-of-date by now. Although I have little experience with other interpreters, I recommend the use of programs such as Zoom instead. Many (including Zoom) offer interfaces of their own and do not require the use of the Mac OS X Terminal program, and some are multi-platform.
Needless to say, it costs me nothing to maintain the package in its present state, but I cannot offer much support at this point for this specific archive. I do not recommend using it, even though it works, unless you have a particular affinity for the Terminal—or need something quick and simple.
Click here to download Frotz.