The Haptik Library Developer's Manual is the main source of info about Haptik. It contains tutorials on using Haptik and how to write plugins, plus the whole reference for every function/class/method in the API. We plan to have exactly the same materials online from this page soon.
Frequently Asked Question
Take a look at the FAQs Section.
The most complete paper about Haptik is:
M. de Pascale and D. Prattichizzo
"The Haptik Library: A Component Based Architecture for Uniform Access to Haptic Devices"
IEEE Robotics & Automation Magazine, vol. 14, no. 4, pp. 64-75, Dec. 2007