Look at it this way. I use only Cave Story's data folder, as well as my own additional data, which remains completely seperate.
This is equal to using the original Doom wad with ZDoom, the commercial Doom wad still being NOT free-to-use (which is why Project FreeDoom exists in the first place) but the source code and engine to ZDoom being completely rewritten from scratch in C++ (as far as I am aware).
The code that I wrote and the data that I made is subject to my terms. The data from Pixel's game is still Pixel's, and I have not modified it or claimed it to be my own in any way, I have not even included it in any downloads thus far, so you still have to get it from Pixel's game in order to use my engine at all.
That is it. That's all there is to it. End all. The reason my game should or should not be open source lies in the libraries I use, most notably SDL, FMOD, and Lua. Nothing to do with Pixel's wishes whatsoever.
... The only thing that goes against this is the music having been ripped from the exe and included, which was necessary because information on how to use it while embedded in the exe is scarce, and the sound effects being included in wav format, the legality of which I'm a bit sketchy on because they are not in their original form.
... ... ...
As for the portability of mods, you should be able to simply take the data folder from your mod, stick your modified Doukutsu.exe in it, name it after your mod, put it in your AGL mods folder, and run Agora.exe -mod Whatever. It won't immediately be fully playable, of course, but it should at least generate the proper map headers. You still need to add config.lua, containing the map, position, health, event, etc. that you start on.
As an example, in the case of Boss Rush, my config.lua currently looks like:
Code:
start.map = 13
start.x = 10
start.y = 8
start.dir = 2
start.event = 200
start.health = 3
title.music = 36
But start.map can also be a file name, and there are a couple more parameters than that (for the intro and title screen) which were omitted for being unnecessary. (And the title screen music is just cool. :3)
Of course, only the first boss has any AI at the moment, and nearly all of the minor enemies beyond the (mimiga) graveyard also lack AI and animation data as well, so there's not much point in porting mods in
UNLESS YOU WANT TO HELP ME WITH THAT, as I have already asked, instead of arguing over the meaningless source code of the game which does little more than load and run the ETE and Lua files.