What is the Drupal API for reading Drupal configuration files (.info .make etc.)? Drupal configurations such as .info, .make appear to follow common structure. There must be Drupal API for reading these configurations from code.

How does one load and read these configurations in his code?
You want drupal_parse_info_format.


  Data should be in an .ini-like format to specify values. White-space
  generally doesn't matter, except inside values.


  key = value
  key = "value"
  key = 'value'
  key = "multi-line
  value"
  key = 'multi-line
  value'
  key
  =
  'value'



  Arrays are created using a HTTP GET alike syntax:


  key[] = "numeric array"
  key[index] = "associative array"
  key[index][] = "nested numeric array"
  key[index][index] = "nested associative array"



  PHP constants are substituted in, but only when used as the entire
  value. Comments should start with a semi-colon at the beginning of a
  line.


I actually know this because the Profiler module uses it to parse out its .info file for profile configurations.