Fish Shell -- Probably the most popular non-POSIX shell (on Linux). Focused on the interactive use case, but also has a new programming language. Written in C++.
PowerShell -- Microsoft's shell that deals with structured data, and has "workflows". Even works on Unix. Depends on a big VM. 850K lines of C# code.
C shell (tcsh) — Command language interpreter usable both as an interactive login shell and a shell script command processor. It includes a command-line editor, programmable word completion, spelling correction, a history mechanism, job control and a C-like syntax. (C Shell on Wikipedia. This is the oldest non-POSIX shell! Originally written by Bill Joy, who also wrote vi, etc.)