XFolder is programmed in C, using the Warp 3 Developer's Toolkit. All XFolder versions until 0.72 were programmed using the IBM C-Set/2 compiler. Thanks to the generous support of Mark Mellin, who sent me VisualAge C++ 3.0, all versions from XFolder 0.80 will have been compiled using that compiler, which has a number of helpful improvements over the earlier IBM compilers.

I'm just a university student in Germany and cannot afford to buy $500 integrated developments, however powerful and convenient they may be. This is why I've been programming Borland Pascal 7 for DOS for years and went on to REXX during 1997, a result of which is my (in my view) very valuable CommandPak package for improving the OS/2 command shell. (It is also available from my homepage.)

I got my C-Set/2 from the German OS/2 magazine "OS/2 Inside", which was said to be the best OS/2 printing in the world. They had a CD-ROM for just some US-$ 20, containing a full C-Set.

I used to have the ordering address on this page, but "OS/2 Inside" has gone out of business, and their ordering shop has reportedly been closed down also. So sadly, I know no way to obtain a cheap IBM compiler for OS/2 any more.

It is still possible to write WPS classes using the great free EMX/GCC compiler, which is available for download at LEO in Germany. The only requirement is a Warp 3 Developer's Toolkit, unfortunately.

While IBM has stated that it will no longer support SOM altoghether, it is still a great technology, although it needs quite a bit of reading until you know what's going on.

The Warp 3 Toolkit contains everything for developing powerful WPS classes. It is sufficiently documented to understand the basic WPS functionality, enabling me (who neither knew C nor the OS/2 API, but only OOP with Pascal and Windows 3.1) to build XFolder's basic functionality (version 0.11) in a triplet of days. (Things become more difficult with more sophisticated features, but that's another story.)

Valuable reading, aside from the Toolkit docs, can also be found in the four IBM OS/2 V2.0 Redbooks, which I found on an old Hobbes CD-ROM and which are still available on the commonly known FTP sites. It is quite outdated (dealing only with OS/2 V2.0), but the system's basic concepts have pretty much remained the same.

I also strongly recommend the Electronic Developer's Magazine for OS/2 on the WWW, which has published fabulous articles on all aspects of OS/2 programming. There are two series about WPS programming, one starting in volume 2 issue 8, the other one in volume 5 issue 10.

If you have the above tools, you should be able to program the WPS in a jiffy. All you still need then is a good portion of patience, since the WPS runs in a single process (PMSHELL.EXE), and bugs in your project will make the whole thing crash repeatedly. Check the helpful "Debugging WPS applications" section in the Toolkit WPS Guide to compensate at least the most annoying problems.