OK, its not a clone (not even close) but I think it kind of has the same flavor to it.
Some of its features seem kind of neat.
FYI http://www.groboto.com/grobot_overview.html
Just for Macs however…
Hi Bidiot
There is place for all 
It’s a great Tools box objects only for Mac Users
Have patience Zbrush will have also animation features for sure 
Training on the fix Images before the nirvana of ZBrush’s animation!
You can make yet animation with the Digit’s Script :cool
Pilou
Excuse my ignorance! you know the GEAR script and coil script if sum brainwave combined these scripts we would have no need for groboto! and there is a tree script sumwhere.
ho it is a mac prog but there are emulators around so you can run it on a pc ill post which is best later . 