AppForge - Microsoft Visual Basic add-in for handheld programming.
CASLsoft: Home Page - Develop PalmPilot applications easily with CASL (Compact Application Solution Language). Commercial software. Demo available for download.
Fred Bayers LispMe - Information about LispMe, a Scheme (Lisp) version for the PalmPilot. Includes useful related files, such as Parentheses Hack.
LispME - A Scheme (Lisp) version for the PalmPilot with related files, such as Parentheses Hack.
NS Basic - A complete development environment for all skill levels.
OrbForms Designer - A complete development tool combining a visual form designer, a smart code-completing source editor, and a rich object-based API.
