Back in 2006, Kevin Forchione wrote rules.t, a TADS 3 extension that added Inform 7-like rules to TADS 3. He's now overhauled it and rewritten it as rulebooks.t. It's a replacement for rules.t, and is more modular than its predecessor.
Iain Merrick has updated Git, his super-fast Glulx interpreter for IF, to version 3.1 of the Glulx spec. Well, mostly -- the malloc and mfree opcodes are still unsupported, so any I7 game that uses lists, for example, won't run on Git. Iain's working on an update to address that as well.
The I7 Thing Creator is a web-based tool for, well, creating objects for Inform 7. You enter information about the object into the form and it generates the appropriate I7 code for you to paste into your game. The big win is that the page lists all of the built-in I7 actions and shows the default responses. By scanning through them you can see that, yes, you should have remembered add a response to LISTEN TO TICKING TIME BOMB.