Plesk API and RPC documents

Documentation Main Page
http://www.parallels.com/ptn/documentation/ppp/
http://www.parallels.com/products/plesk/documentation/

Plesk API Developers Guide
http://download1.parallels.com/Plesk/PP10/10.4/Doc/en-US/online/plesk-api-rpc-guide/

Plesk API RPC referrence
http://download1.parallels.com/Plesk/PP10/10.0.0/Doc/en-US/online/plesk-api-rpc/index.htm

PHP functions and example
http://download1.parallels.com/Plesk/PP10/10.4/Doc/en-US/online/plesk-api-rpc-guide/index.htm?fileName=33181.htm