Titled RPG Tsukūru in Japan, the RPG Maker series are very easy to use RPG making programs mostly for Windows, and sometimes for consoles and Japanese PCs. The Windows versions became (beginning with RPG Maker 95) popular outside Japan due to fan translation1), eventually leading to them being released in the west commercially, beginning with RPG Maker XP in 2004-05.
People wanting to play games made with the Windows versions will usually have to download something called an RTP2) relevant to the version of the program the game was made with. The RTPs are the collection of assets provided with the program, and come included with the softwares' downloads. They can also be downloaded as free, standalone, archives.
The software is generally very easy to use. 'Programming' is done selecting commands from a menu (though XP, and VX, users can also use Ruby. Resource editing is possible in some of the console versions, but on Windows graphics, music, and sound effects, must be made in other software. Though, as mentioned, there are plenty of resources supplied with the software.
The second SNES version was unofficially translated into English. There's not much reason to play it instead of the other releases, but it's interesting. The games play a lot like the earlier Dragon Quest games; there's even menu based searching, and stair using. The game comes on a Super Game Boy-esque cart, which takes Satellaview memory packs, allowing resource data to be downloaded, but not swapping of games. The prequel was compatible with the Turbo File Twin, which allows game files to be kept off-cart.3)
Often called simply RM95, this is the first Windows version, and, unlike the next two on the platform runs in 640×480 resolution. Otherwise it is quite similar to use.
RPG Tsukuru 3 in Japan. The first version for the Sony PlayStation. It's still 2D, and not that much different than the second SNES game, though it added the ability to make your own graphics, and included more resources.
The sequel, RPG Tsukuru 4, also a PlayStation game, was never outside Japan, and is untranslated. Apparently it's the top of the 2D console games, and features Final Fantasy-style combat.
RPG Tsukuru 2000 in Japan, and usually RM2k elsewhere. This is where the series really got popular, with Don Miguel's translation. The community, at the time, also revolved round his website. The program runs in 320×240, which makes graphic creation mostly easier. It also means a lot of people rip graphics from 16-bit era games. Battles are still Dragon Quest-style, but people have found ways to get round that using events. Results are mixed.
RPG Tsukuru 5 in Japan. Not to be confused with the translation of the second SNES game. This was made for the PlayStation 2, and while the graphics are crude, the program difficult to use, it is really flexible. It works unlike anything else in the line.
RPG Tsukuru 2003 in Japan, and often goes by RM2k3. A tweaked version of RPG Maker 2000, really. Unfortunately it seems a bit rushed, as some features that are added aren't as flexibly controlled as in 2k. There's a side-view battle system, though its ATB4) is a bit of a mess, even when turned off. So, some people still prefer RM2k.
Runs in a higher resolution than the 200x programs, and was officially released in English.
Just RPG Tsukuru in Japan, suggests a relaunch, or sorts. Much more focused the the previous PS2 version. Easy to use, though aimed at making only 'medieval' games, with no ability to make resources yourself, though terrain can be modelled, somewhat.
A few notable examples are able to be found among the Final Fantasy Fan-game Drivel.