FreeOTFE4PDA is an "on-the-fly" (OTFE) transparent disk encryption program. Using this software, you can create one or more "virtual memory cards" on your PDA. Anything written to one of these cards will be automatically and securely encrypted before being stored. A PC version is also available, allowing data encrypted on your PC to be read/written on your PDA, and vice-versa.
swampex (or Swamp Explorer) is a cross-platform library designed to work with raster maps in Ozi Explorer format. Using this library, you'll be able to collect maps in the file system, get information about map calibration, find maps by latitude/longitude, render maps in SDL surfaces, and more.