execute GRASS commands outside of GRASS?

Is it possible to run GRASS commands from a non-GRASS program or from the
system prompt? If so, what extra details do I need to track?

I have looked at some of the shell scripts in the src/scripts directory but
they expect to be called while GRASS is running (from the GRASS prompt).

Any pointers or suggestions would be greatly appreciated.

Virginia Jackson
Engineering Research Associates
jackson@era.com