bash
----
Bash is an sh-compatible command language interpreter that executes
commands read from the standard input or from a file.  Bash also
incorporates useful features from the Korn and C shells (ksh and csh).

Bash is ultimately intended to be a faithful implementation of the
IEEE Posix Shell and Tools specification (IEEE Working Group 1003.2).

Bash is available from GNU sites, such as jaguar.cs.utah.edu:gnustuff

tcsh
----
is an enhanced version of the Berkeley UNIX C shell csh.  It behaves
exactly like the C  shell, with added utilities of:

1) Command line editing using vi or Emacs commands, allowing you to
   correct errors in the current input line, or in previously input lines,
   much more easily than with sh or csh.
2) Visual step up/down through the history list, letting you recall
   previously typed lines by simply pressing the up arrow key.
3) Terminal mode sanity checking and resetting, which helps reduce
   problems for users who frequently switch between various types of
   terminals.
4) Interactive command, file name and user name completion, allowing you
   to type the first few characters of a command, user name, or file name,
   then press the TAB key to automatically complete the word.
5) File, directory, and user list display in the middle of a typed
   command.
6) Interactive spelling correction of command, file, and user names.
7) Lookup of command documentation in the middle of a typed command. 
8) Enhanced history mechanism for recalling previous commands.
9) Automatic locking or logout after long periods of idle time.

You can get the tcsh distribution from

ftp://ftp.deshaw.com/pub/tcsh
  or
ftp://ftp.primate.wisc.edu/pub/csh-tcsh-book
http://www.primate.wisc.edu/software/csh-tcsh-book

You can also get extended installation instructions at the primate.wisc.edu
locations, in the form of a downloadable chapter from the tcsh book.

(Sites submitted by Paul DuBois dubois@primate.wisc.edu)

zsh
---
(paraphrased from the zsh faq, posted to comp.answers monthly)
zsh is a UNIX command interpreter (shell) which of the standard shells
most resembles the Korn shell (ksh), although it is not completely
compatible.  It includes enhancements of many types, notably in the
command-line editor, options for customising its behaviour, filename
globbing, features to make C-shell (csh) users feel more at home and
extra features drawn from tcsh (another `custom' shell).

zsh is available for users east of the Atlantic from:
  carlo.phys.uva.nl(145.18.218.21):/pub/bas/zsh/zsh-2.4beta.tar.gz
The latest full release is in zsh-2.3.1.tar.gz in the same directory.
and
  ftp://ftp.sterling.com/

The 2.3.1 distribution is also available from ftp.uu.net and mirrors
in the directory pub/shells/zsh.

MC File Manager
---------------
a portable user-friendly file manager for Unix systems licensed under the
GNU GPL.  The program is available in ftp.nuclecu.unam.mx in the directory
/linux/local and its name is mc-1.2.tar.gz.