  This guide is intended to knit together, and extend, the existing PP and C documentation on PDL internals. It draws heavily from prior work by the authors of the code. Special thanks go to Christian Soeller, and Tuomas Lukka, who together with Glazebrook conceived and implemented PDL and PP; and to Chris Marshall, who has led the PDL development team through several groundbreaking releases and to new levels of usability. 
Practical Magick with C, PDL, and PDL::PP -- a guide to compiled add-ons   for PDL