The Sherpa shell is an interactive command line environment. Where Tk is available, it opens in a Tk Text widget. All commands in the shell are accessible directly via the command line.
The help command gives reasonably helpful reference information about the tools provided by sherpa. Areas of support include archive packing/unpacking, building packages from source, retrieving packages from the teapot, and populating virtual file systems for other packages.
Any command which is not understood by sherpa itself will be interpreted in the global interpreter. If the output is green, sherpa is responding. If the output is blue, the command was evaluated using bare tcl. If the output is red, there was an error.