sudosh can be used as a default login shell or a filter that takes advantage of PTY devices in order to sit between the user's keyboard and a program, in this case a shell. It was designed specifically to be used in conjunction with sudo, and allows the execution of a root or application shell with logging. It is basically a VCR and will record root shell sessions and also has the ability to play back the sessions as they were originally recorded. It records all input/output, keyboard input, and timing information so that the session can be played back in the original format.
Zoidberg (a.k.a. zoid) provides a modular Perl shell written, configured, and operated entirely in Perl. It aspires to be a fully operational login shell with all the features one normally expects. But it also gives direct access to Perl objects and data structures from the command line, and allows you to run Perl code within the scope of your command line.
Wsh is a remote Unix and Windows NT shell that works via HTTP. The client script provides a shell-like prompt, encapsulating user commands into HTTP POST requests and sending them to the server script. The server script extracts and executes commands and returns STDOUT and STDERR output. Features include command line history support, file upload/download, and it can work through an HTTP proxy server.
Mail2sh makes it possible to carry out shell commands by email. Email is sent to a particular user on your host and the commands will be carried out if the user and password given matches ones in /etc/passwd. Commands are executed with the user's privileges, and combined with a PGP module ensures a certain level of security for use. Note that the system is not natively encrypted, so use of an encryption mechanism is highly recommended for security reasons.
NOTE is a small console program that allows you to manage notes similar to programs like "knotes" from the command line. It supports different database backends for storage, and includes a DBI-based MySQL module and another module that uses a binary file for storage and a DBM module.
XSH (the XML Editing Shell) is a very powerful command-line shell designed to allow easy navigation and manipulation of XML documents. XSH may be used either interactively or for off-line XML processing (like bash). XPath can be used to select parts of an XML document to be listed or processed. The system shell and Perl are also accessible from XSH in a very natural way. XSH itself is written in Perl using the XML::LibXML bindings of the libxml2 library.