The OHRRPGCE was originally inspired by a game maker called ACS which James Paige played on his cousin's computer when he was... 12? 14? He doesn't remember when exactly, just that it was before he knew how to program or even owned a computer of his own. After learning QuickBasic and making a few games, James learned that making a data-driven editor for a game can be more efficient than hard-coding the game directly in a programming language. (20 years later, James realized that "fun" probably would have been a better word to use than "efficient")
In late 1996 James started programming Wandering Hamster, and building a generic game-editing tool for it. He named it O.H.R.RPG.C.E for Official Hamster Republic Role Playing Game Construction Engine.
The first public release of the OHRRPGCE was in late 1997 or early 1998 (I forget), right after James finished the battle system. (I think?)
Originally, James entertained ideas about selling the OHRRPGCE as shareware. The original release was crippled to only allow 4 maps.
People asked for more maps, and so after a while, James started offering an uncrippled version to anyone who would mail him a good game (to prove they were serious). After a few months of that, James was getting sick of answering e-mails, and was feeling bad about setting himself up as judge of which games were "good" or not, so he gave in and released the first uncrippled version.
In June of 1999, James realized that it would be a good idea to start keeping a log of changes. That log is whatsnew.txt. It is organized by stable release, and shows the oldest changes at the bottom and the newest changes at the top. You can get a good overview of how the OHRRPGCE has evolved over time by reading it.
The November 9 1999 release of the OHRRPGCE added support for plotscripting. Plotscripts are a programming language that can be embedded into your game, allowing for complex cutscenes where the characters move around and talk under computer control. It is flexible enough that people have used plotscripting to implement entire games, such as side-scrollers, puzzle games, or tactics engines using it.
Starting shortly before the quaternion release, James released the source code to the OHRRPGCE under the GPL. This revived interest in the OHRRPGCE, which had not seen an update in almost a year. Since then, the OHRRPGCE has been developed by a team of developers.
Not long after the source was released, Simon Bradley started porting it from QuickBasic to FreeBasic. This port removed the awful real-mode memory limitations that had held the OHRRPGCE back for so long. The FreeBasic version runs natively in Windows and Linux rather than needing to run in a DOS box. Simon's Freebasic port was integrated back into the main development tree, and starting with the serendipity release, Freebasic has become the main language for OHRRPGCE development.
After the hasta-la-qb release, development of the QuickBasic version was abandoned, and the developers started to use language features that are only available in FreeBasic
Linux, Mac, Android
The OHRRPGCE was ported to other platforms, so in addition to Windows, it also runs on Linux, Mac, and most recently Android.
Has not been written yet.