An enhanced but completely compatible version of the Berkeley C shell, csh.
Ranked in these QuestionsQuestion Ranking
Pro Organized documentation
All the documentation that's needed to use tcsh is located in
man tcsh instead of being spread on various helper programs.
Pro C-like shell
It's a C-like shell with tenex command-completion feature, which is very convenient.
Con Limited support online
The support and number of guides and tutorials is rather limited for tcsh online because there are not many people who use it. At least compared to some of the other more popular alternatives.