If you're addicted to programming in C or if you simply want to practice the discipline on the bus then look no further than OnBoard. This compiler is designed to run your own developments in C and generates executables compatible with the Palm platform.
From its primary user environment you can create a new project, load an existing one, edit your source code structures and generate and compile files. For editing, OnBoard allows you to use one of the following editors: QED, Zdoc, SmartDoc, WordSmith or QuickWord. Because the program includes its own library functions, you don't need to install any extension or additional database to process your developments.
If you're keen to develop apps for the Palm and have a good knowledge of C then OnBoard represents a very robust solution.