Name 

Description 

__KEYPAD_WIDGET_DEFINED__ 

This is macro __KEYPAD_WIDGET_DEFINED__. 

KEYPAD_NAMESPACE 

keypad.c 

KEYPAD_NAMESPACE_END 

This is macro KEYPAD_NAMESPACE_END. 

KEYPAD_PROC 

This is macro KEYPAD_PROC. 

Name 

Description 

sack 

It's called System Abstraction Component Kit - that is almost what it is, self descriptively, but that's not what it entirely. It's more appropriately just a sack-o-goodies. A grab-bag of tidbits. The basic aggregation of group of objects in sack is bag. Bag contains everything that is not graphic.
It abstracts loading external libraries (.dll and .so shared objects) so applications can be unbothered by platform details.
It abstracts system features like threads into a consistent API.
It abstracts system shared memory allocation and management, does have a custom allocation and release method, but currently falls back to using malloc... more