Spatterlight is a native Cocoa application plays most kinds of interactive fiction game files: AGT, Adrift, AdvSys, Alan, Glulx, Hugo, Level 9, Magnetic Scrolls, TADS (text-only), Quill, and Z-code (except v6).
Spatterlight also supports the Treaty of Babel standard for cataloguing bibliographic information about interactive fiction.
The Spatterlight application is released under the GNU Public License; the interpreters and libraries it uses are freely redistributable and covered by their own specific licenses.
Look at the screenshots here.
You can find downloads and more information about Spatterlight on github.