anchor.diff:  http://neugierig.org/software/chromium/notes/2011/02/ninja.html[my
   work on the Chromium browser project], which has over 30,000 source
   files and whose other build systems (including one built from custom
  -non-recursive Makefiles) can take ten seconds to start building after
  -changing one file.  Ninja is under a second.
  +non-recursive Makefiles) would take ten seconds to start building
  +after changing one file.  Ninja is under a second.
   
   Philosophical overview
   ~~~~~~~~~~~~~~~~~~~~~~
  
positive.code: 
  ----
  rule demo
    command = echo "this is a demo of $foo'
  
  build out: demo
    foo = bar
  
negative.code: Comparison to Make
  ~~~~~~~~~~~~~~~~~~
  
  Ninja is closest in spirit and functionality to Make, relying on
  simple dependencies between file timestamps.
  
  But fundamentally, make has a lot of _features_: suffix rules,
  