Is the PD file format documented anywhere? (besides the source code)?

Has anyone built any programs which build PD files? 

It might be neat to have a C-Sound or Supercollider style language (where writting tests and loops can be easier) which compile down to a .PD source file. 

I'm sure I'm not the only person who has thought of this! 

I realize that editing .PD files directly is generally considered to be "nicht für der gefingerpoken".... ;) 

thanks