I am looking for infocom IF titles for the z machine - I can find any number of DOS executables for everything but nothing platform independant.

I can find any number of zmachine IFs too - but not from infocom.

Well all right, I have found:

Hitchhikers Guide to the Galaxy; Planetfall; Leather Goddesses of Phobos.

I know the Zork trilogy exist on z machine because I had them on my pocket PC. I( cannot for the life of me figure where I got tem.

I'd espacially like Trinity, A Mind Forever Voyaging and the sequel to planetfall but google shows nada.

Right - easy mistake.

While there are dos executables which are completely sealed, this is not the normal mode of distribution.

The original dos distribution contained a z-machine interpreter as a .com or .exe file, and the z-code in a .dat file (which modern OSs think is an mpeg file). Relabel this .z5 and it is fine with frotz. Or just frotz IFgame.dat.

The home of the underdogs has a great deal of interactive fiction, including the old infocom stuff and scans of the manuals and freebees. (Important since that was the form of copy protection used back then, and still now I guess.)