What is instead of WinDDK in Linux?

[SiNTAX]

Or as they say... Use the source Luke...
And if that don't work, checkout hxxp://www.kernelnewbies.org/ -- which was setup specifically to answer these kinds of questions.
Reading LKML (Linux Kernel Mailing List) would also be a good idea.

Forgot this one.. useful for people with kernel 2.4 knowledge, but also has lotsa good info for other people:
Porting device drivers to the 2.6 kernel
hxxp://lwn.net/Articles/driver-porting/

and.. the historical resting place of
Linux Device Drivers, Second Edition
hxxp://lwn.net/Kernel/LDD2/index.lwn

[EDIT JMI: Don't answer your own Posts. That's what the edit button is for!]