Years ago (10? 15? hard to say) I wrote an IF game. I did not complete it. I don’t know what program I used. I’ve recently uncovered it and learned through Googling that I can play my D$$ file with AGiliTy and run the game.
Questions:
(1) What can I use to “open” the file(s) and continue its development?
(2) How can I “port/convert” the game so that it becomes playable through people browsers?
This game was written in AGT, the Adventure Game Toolkit. Nobody uses that anymore, and the tools are mainly just for MS-DOS (and a few even more obsolete systems). AGiliTy just exists so we can keep playing the old games; no one’s maintaining tools to make new ones.
It doesn’t sound like you still have your game’s source code. If you can find it, I suggest re-writing the game in a modern system. If not, there does exist a decompiler (which you could run in DOSBox or an emulator), but I don’t know how well it works.
You can find the existing AGT tools on the IF Archive here.
I’m not an AGT author, but I ran into a similar problem trying to get an AGT game running a while back. Maybe it’s related.
AGT, it turns out, is picky about filename case. This turns out not to matter in DOS, because (if I recall correctly) DOS is itself case-insensitive about filenames, so AGT running under DOS helpfully found (lowercase) cory.d$$ when your original AGT tools asked for (uppercase) cory.D$$. Many modern operating systems are less accommodating, and third-party tools may not be as lenient as the original official AGT tools.
Try changing all of your file extensions to uppercase and see if that helps.
There’s the magx compiler in the IF archive, whose run on modern OS and there’s Gargoyle Agility interpreter, so can be completed and played in a modern environment.
I actually toyed & messed with magx and play old AGT games in gargoyle agility.