#1. All user data (that should remain when upgrading or uninstalling) needs to be placed in a) a folder that is universally accessible and b) outside of the root Game folder so that it can be kept 'safe' from accidental removal and modification by average users.
Oops, forgot to take that into aspect, since, like Mr War, I save mods into the installation directory. In which case, the paths suggested could still be used, but relative to the "data folder". Of course, like techs, you could still use the installation directory.
[data folder]/conversions/[mod name]/techs
/maps
/tilesets
#2. The windows version of Megaglest Includes a shortcut to the user data folder in the Mega Glest menu which should be sufficient for average users wanting to find this data. (For modders etc. nothing stops you from creating a shortcut to the userdata folder in the root MG folder for quick access)
Remember we are looking for solutions that work in Windows XP --> Windows 7 as well as other platforms (like Linux and Mac). To customize behaviour differently for every platform adds more complexity to the code so this route is often frowned upon.
If we're really going to get into that conversation again,
%USERPROFILE% works on Windows 2000, XP, Vista, 7, etc. It directs to the user's personal folder (
C:\Documents and Settings\[user name] on Windows 2000 and XP;
C:\Users\[user name] on Windows Vista and 7). This is where most games save on windows.
In
%USERPROFILE%, I several programs create folders to store their data, including GAE (which has not had a single issue with that folder location, and is just as cross platform as MG), scorched3D, the GIMP (you all use that one), and Jagex preferences. Under
%USERPROFILE%/My Documents, I have a Bioware folder for Mass Effect and Dragon Age, a Battlefield folder, Witcher 2, Need for Speed Most Wanted, Visual Studio, Warzone 2100, Sony Vegas Movie Studio, and of course, a "My games" folder which contains subfolders for Dirt2, Halo, Oblivion, Skyrim, and Civilization 4. That many programs can't be wrong.
Oh, and yeah, for the "other side", we have a quite a few folders in app data, sure, but I can't find a use for them. Opening a random one (Ashampoo), I got nothing but a few log files. Oh, and there's a dropbox folder here, wierd, I uninstalled that months ago. It contains a single installation log and a bunch of useless files without extensions. The microsoft folder is pretty full, but it's mostly temporary files that aren't used anymore, empty folders (huh?), and a few "no-touchy" files, such as settings stored in binary (meant to be changed from the application itself). In other words, programs (and games) that are supposed to be modified or expanded keep their stuff in the user folder (well, except skyrim, it wants its mods in the installation directory, but the INIs (loads of settings can only be changed in the INI) are in the personal folder, go figure). App data is for storing stuff you don't touch. Mods and INIs, keep out.