Whisper
- a general purpose Mac/Win32 C++ application framework. It's the successor to the Mac framework Raven. Offers development status, statistics, notes, and downloads.
- http://sourceforge.net/projects/whisper2/

Macintosh Application Development Essentials (MADE)
- a tiny package of C/C++ code which provides all the lowest-level needs for a Macintosh application. It is designed for people who are learning, or know how to program Macs, but don't have the time, energy or desire to write basic menu, event, memory and e
- http://www.sigsoftware.com/made/

CPLAT
- a low-cost C++ cross-platform framework
- http://www.ksoft.net/cp_home.htm