Sadly I lost the source code for it the same year from a hard drive failure before I was using GitHub.

It's rather simple, it just makes a fake source mod and modifies the gameinfo.txt to load assets. For figuring out what games they had available I just looked through everything in their steam directory for known source games. The code was also really really poorly made. 80% of it was just a giant switch statement.

This is the rewrite I started on a few months ago https://github.com/Jesse-Culver/SourceMultiTool_CSharp/blob/master/SourceMultiToolCSharp/mainMenuForm.cs
I didn't get very far with it before I had to stop to focus on some other stuff.

For Gmod though I later found out you can just change the mount.cfg (garrysmod/cfg/) and it mounts whatever you put in there which is probably what you want. It also will mount any files found in the addons folder as long as it is setup properly (e.g. addons/myassets/models/house/myhouse01.mdl)

You won't mind if I take a peek at the disassembled sources? :)
dotnetpeek is pretty much spot on for this stuff. Mostly just interested in the creating of a fake source mod tbh.

My plan is to make a tool that creates an enviroment like the one I have had before, where I host hammer in a sourcemod area, so it can see all of the custom textures and whatnot, and then just copy and run gmod. I have a tool that automatically bakes in all the textures and generates cubemaps, so it's pretty much just the setup that is needed. Sorry, ranting along :').

Yeah that's fine!

But really all I did was take what I wrote in this guide and automated it a bit, keep in mind the tool has a fairly bad bug on my part for finding what you have installed. I assumed at the time the registry entry for Steams install location would be the only place players would have games installed since I never considered people having multiple hard drives. https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=187235526

Yeah, took a peek, and then took a little walk along the steam configs. Turns out there are two files with all the paths to the different steam stores (I have two on my computer, so, yay.). So just need to parse that out (or, heh, just do a filthy filllthy regex). Then again, that's just for finding defaults I guess ;).

Yeah, my newer one just looks at libraryfolders.vdf which is a much better way of handling it. Best of luck with your tool!

Yo. I have started to cobble together something with a mix of my code, your code for v1 and v2, at https://github.com/magnusjjj/TuxieLaunch .

Can we license it as some open source license? I mean, there is a LOT of copy paste in there :')

Sure if you want to throw a GPL license on it that's fine.

Any updates on this? I was trying to see if I can get this going, I can't find the installer for the updated tool

Do you still have the hard drive? Would a recovery option be possible?

The drive physically failed. It's not a complicated tool and most of what it does is in the link above.