New SCI decompiler takes all the guesswork out of poking around old Sierra games
ScummVM dev Sluicebox just blew the doors to the Sierra kingdom wide open. He wrote a decompiler that annotates the decompiled scripts flawlessly so there's no more guesswork as to "uh, I wonder what 'global34' does."
As a software engineer myself, this was a really interesting read and it's amazing how far the community has come with these tools to dig around in, make their own games with the SCI engine, and now total decompilation of the scripts with comments and annotations included with them.