title: Replacements for the C preprocessor
body: <p>I'm interested in using something other than the <strong>C</strong> preprocessor to preprocess my <strong>C</strong> and Objective-C source code.  Are there good alternatives?</p>
  
  <p>An example would be something that allowed one to escape out into a python or perl snippet in the middle of <strong>C</strong> code, and where the snippet spit out <strong>C</strong> that is then compiled as normal.</p>