Raptor base

Files in mozilla/base/src/os2/
(not yet checked in to mozilla.org cvs)

nsTimerOS2.cpp

Timers are used to invoke a function or method after a specified time. The current implementation uses WM_TIMER to do this. Separate threads use separate windows and timers, so that timeout functions get called in the thread from which the timer was set.

Look at removing PM dependency
(This isn't so important, the current method seems fine)

nsFileSpecOS2.cpp

These classes are designed to provide a cross-platform abstraction of file names and conversion to file:// URLs (abstracting; see nsFileSpec.h for more).

nsCaretPropsOS2.cpp

This provides methods to get metrics for the caret, the blinking vertical cursor used in the editor.

Caret width is fairly arbitrary at the moment; the real fix is to move this function into the nsILookAndFeel interface in the widget library and to change the API to request the width of the caret in pixels as opposed to app units. This is a cross-platform change, which should go through the editor team.

There's also platform-specific code in the main base library, in nsSpecialSystemDirectory.cpp, which is used to find the temporary directory, and so on.