DSLR computer control?

[David Bean]

Is there any software available to operate the Pentax DSLRs from a computer?
What I'd like to find would, at a minimum, show the live image on the
computer screen and allow the shutter to be released from the keyboard.  (It
would be nice to be able to do everything the camera's electronic controls
allow, of course)  Do you know of such software for any other brand DSLRs?