> You could even split things into three layers: a layer for the OS (Windows 95, say); a layer for the game engine; and then a layer for the game project. And the whole thing gets "pulled", revived into a merged container, and then loaded into DOSBox.

You can do this today with dosbox on archive.org. Here's how:

Upload the game engine (Doom, to keep with the current theme) as an IA item; this may or may not have already been done (I happen to know that Doom is hidden because you can buy it on Steam, but I'm pretty sure the shareware version is there somewhere). For the sake of this example, assume that your item has "foo" as its identifier, and the game is in "foo.zip".

Then upload your game or level (WAD, in this case) as another item. Assume that this one is called "bar", and has a "bar.zip" containing the level and a batch file that I'll describe.

Edit the metadata for your item named "bar" so that it includes this information:

  emulator=dosbox
  dosbox_drive_c=foo/foo.zip
  dosbox_drive_d=bar/bar.zip
  emulator_start=d:\bar.bat

The batch file "bar.bat" is responsible for starting the game, which might include copying files, changing config files, specifying command-line arguments, etc.

If you want to use windows you can use the same system to load it as well. Of course this really only works with the earlier versions of windows which ran in dos, and thus can run in dosbox. Check out https://archive.org/details/win3_SKIFREE for an example.

You can also host everything on your own webpage; I recommend my own project, the Emularity, which simplifies a lot of it (http://emularity.com/).