Inform is developed by Graham Nelson, whose pages at www.inform-fiction.org provide a good starting point.
The Inform authoring system consists of a compiler and an interpreter, both of which are available for many popular platforms. The object-oriented source language, reminiscent of C, is compiled into Z-code (as used by Zork and many other Infocom games); this binary code is processed by a Z-machine interpreter at run-time.
Quoting from the FAQ for the rec.arts.int-fiction newsgroup:
It is the most highly ported authoring system, and is quite popular. It is very powerful; some of the very advanced techniques are difficult to understand, though. Though it has a few more ports than TADS, HTML-TADS' graphics and sound support are both more powerful and more usable (at the current time) than Inform's. Also, the Z-Machine suffers from the fact that extraordinarily large (and I mean really really big) games do not fit in it. However, for a normal-sized, text-only game that doesn't do extraordinarily complicated hacks (most games fit this description), Inform's problems do not hurt at all.
Read the complete Inform entry at www.plover.net/~textfire/raiffaq/FAQ.htm#Inform or the entire FAQ at www.plover.net/~textfire/raiffaq/.
The Inform version of "Cloak of Darkness" was written by Roger Firth (firstname.lastname@example.org).
NOTE: These pages focus on Inform 6 -- the current version of the system. Inform 7, a completely different approach to IF authorship, is nearing completion; you can see an Inform 7 implementation of "Cloak of Darkness", by Emily Short and Graham Nelson, at the end of the source listing, and both source versions are included on the download menu.