Go to the Roguelikes for PalmOS project page on SourceForge. Download the "kMoria module" (it should be listed in the File Releases section).
I've used prc-tools 2.0. I'm running Linux.
You can get prc-tools from palmsource.com. Follow their directions for installation. You will need PilRC as well (version 2.7b or greater).
SDK - The current version of kMoria uses SDK 3.5 or higher. (Versions prior to 0.09 use SDK 3.1, and would need header files changed to compile with anything more recent.)
multigen - Since kMoria is large, it has "multiple code resources" and uses multigen. You might want to read about that in the prc-tools documentation.
emulator - The safest place to test software is in a Palm emulator. You will need a ROM image to use it.