Did you ever look in detail at Common Ground? IIRC, it was not only an Adobe PDF alternative, but the format was considerably more modern and powerful. Sadly, it seems like it lost just because PDF was similar to PostScript, a fact that never really made any real difference to anyone but programmers writing PDF parsers. (And PostScript smelled like the future, since Display PostScript was the basis for displays (well, kinda) at NeXT and Sun, and those were definitely the cool kids...