osfree.org

OS/2 server
The main server of OS/2 personality. Handles the system initialization and the base set of API's

File system server
Server which loads IFS'es and handles file system-related API's

Exec server
Server which loads IIF/IXF drivers and implements dynamic executable file loader. It also implements the shared arena

MVM server
Multiple virtual machines server. Implements a hypervisor and handles virtual DOS machines. Also, it loads VDD drivers as its plugins

CPI
Control program API, resides in DOSCALLS.DLL

VIO
Video input/output, the console API

Command line tools
This forum for discussion about development of CMD.EXE & command-line utilities

GPI and GRE
Discussion about development of graphics subsystem (Graphical Program Interface and Graphics Runtime Engine API's)

Presentation manager
Presentation Manager (windowing subsystem) development questions.

Multimedia subsystem
Multimedia sybsystem (MMOS/2)