sash-plus-patches is a collection of patches for the well known standalone shell, sash. The key features are the chroot, pivot_root, and losetup functions. These functions provide interfaces to the respective Linux system calls. They are especially useful when sash is used in a initial ramdisk ("initrd") environment. In addition, simple shell variable expansion support has been added.
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.
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.
execline is a very light, non-interactive scripting language, which is similar to a shell. Simple shell scripts can be easily rewritten in the execline language, improving performance and memory usage. execline was designed for use in embedded systems, but works on most Unix flavors.