The SCUMMBag family is a suite of tools for SCUMM related stuff, consisting of the family members SCUMM Revisited 4, ScummIDE (complete application to make new games in SCUMM), WinSPUTM (similar to scummvm) and iMUSE Player (for playing iMUSE MIDIs (and maybe digital music) interactively). And with the friends of the family - the family only has one friend, so far - the CMI Decompiler. None of these programs are finished yet. Most of them haven't even begun. None of them might ever BE done. There'll be a site for it all sometime soon, hopefully.
As far as I recall, SCUMM Revisited doesn't really support anything from the old games - Maniac Mansion and Zak. They use a completely different format that I never did much work on. SCUMM16 found at LucasHacks! (as far as I recall) opens those files, though. And SCUMM Revisited 4 - if it ever gets released - probably will too.
Annotation files allow you to name any block in SCUMM Revisited with a descriptive name, so that blocks are easier to locate.
File dump saves the currently selected block to a file of its own. It's mainly intended for SCUMM developers to investigate single blocks in other programs.
Flash files store the hierarchy of a SCUMM resource file in a format that is faster for SCUMM Revisited to turn into the tree you see when opening a file. This is especially useful for the MONSTER.SOU files which may take a long time for SCUMM Revisited to analyze.
There's much more info on all three file types in the SCUMM Revisited help file (and the online help).
I have no idea where Weevil's Annotation Assistant has gone. I haven't heard from Weevil for years, so... Not sure.