What is Tcsh?
Tcsh is a command language interperter with interactive login shell and command processor functionality. Tcsh is an improved version of csh shell with new features and functionality. Some of the many features that Tsch includes are a spellchecker,command-line editor, programmable autocomplete, as well as an enhanced history feature. Users familiar with csh will find more customization and flexibility options available in Tcsh.
The name of the actual executable is tcsh at:
Enabling Tcsh as default
You can change your shell in the panel at (Panel > 'Users' > 'Manage Users').