xad.hwp was written by Andreas Falkenhahn. Work on this project was started in early 2014 as a proof-of-concept demonstration of Hollywood 6.0's powerful new file and directory adapter plugin interfaces which allow plugins to hook into Hollywood's file and directory handlers. xad.hwp makes use of this feature by making Hollywood think that archives supported by the XAD system are just directories so that it is possible to iterate through them using Hollywood's normal directory functions or open files within archives without extracting them first.
If you want to contact me, you can either send an e-mail to andreas@airsoftsoftwair.de or use the contact form on http://www.hollywood-mal.com.