Pocket Scheme
If you're a LISP or Scheme programmer (Scheme is, loosely termed, the modern standard for LISP) you can't go wrong with Pocket Scheme (at http://www.angrygraycat.com/scheme/pscheme.htm), a full Scheme programming environment that the developer insists will always be free.

It installs quickly and easily and, while it is an alpha release, appeared to be quite robust. I am not a Scheme programmer, however, so I didn't test the environment extensively. Scheme leans heavily toward manipulation of lists and is oriented toward console-mode output. It's much better for writing pattern matching code, AI programs, and text processing than it is for the creation of Windows CE games or utilities. Unless, of course, the game happens to be Hangman or the utility happens to involve chewing through those many vast text files you store on your Windows CE machine.

A noteworthy feature of Pocket Scheme is that it is extensible through DLLs, although the Angry Gray Cat Web site warns darkly that its API "is not a thing of beauty. There is no documentation and no development kit: use the source." It would in fact be straightforward to develop a forms package for Pocket Scheme by writing a DLL in Visual C++.

Basice
Basice (at http://www.jps.net/deang/basice.htm) is a language to watch. While in a rudimentary, freeware form right now, it's already close to the QBASIC of yore, but for a Win32 host instead of DOS.

The sample programs include a simple terminal program, graph plotting, and rudimentary graphics. Another distinct improvement over GWBASIC is a simple form of code sharing through the use of a library directory. You can develop programs either interactively or using a text editor. Basice has built-in support for graphics, file handling, string handling, math functions, error handling, and serial I/O. Its documentation is amazingly good for a free product and would already be acceptable for a commercial product, although currently there's no charge. I suspect there will be as it improves. It is well worth the price--check the Basice Web site routinely if you're interested in programming on a Windows CE machine. It's not yet ready for prime time, but I have high hopes for it.