TWAIN shell

[viktoras d.]

I found a piece of software that should allow me to automate 
communication with any TWAIN imaging device (camera, scanner, etc) from 
within my Rev applications on Windows: 
http://www.dosadi.com/acquire.htm. Unfortunately it is not free and 
limited to MS Windows only.

Does anyone know anything better than this ? Any TWAIN-like standards 
and related command line utilities to access imaging devices on MacOSX? 
Linux?

Viktoras