Jal is a simple programming language that is free to use and easy enough for your students to learn in a half year course. It is a compiled language which means it runs much faster than the interpreted languages like the the basic stamp. To ease the pain of compiling, loading and runing your code, I use a bootloader called Tiny Bootloader. Using a bootloader will dramatically speed up the programming cycle. Jal and a bootloader is nearly as easy as programming for the basic stamp. With two clicks you'll have your new code compiled and programmed into your pic. You'll need a few things to get started.
1. A Microchip Pic16f88. This is the brains of the beast and will cost you between $2.50 and $4.00 at mouser or digikey depending on how many you buy. A basic stamp will set you back $25 or more. Be sure to get the PDIP version for solderless breadboards.
2. A solderless breaboard. The small ones are good for the robotic car, larger ones are good for other projects that don't move.
3. A high voltage programmer such as the picstart programmer or any other programmer that works for Pic microcontrollers. You only use this to load tiny bootloader onto the pic. Afterwards you will use a simple serial cable.
4. Jal: This is the programming language. You'll find example code in the worksheets in the downloads section. There is a great mailing list on yahoo groups called the jallist where you can get ideas and support. Jaledit is included and works great as an editor.
5. Tiny bootloader: This is how you load your code. Use the high voltage programmer to load the hex file "tinybld16F88_i8MHz __19200.HEX" from the /picsource/16f folder onto your pic. This assumes you are using the internal clock and not an external crystal to clock your 16f88. Then bring up the tinybootloader software and set it to 19200 baud.
6. A serial cable with a max232 voltage level converter. There are instructions and a schematic on the tinybld website and in the tiny bootloader download above.