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.
Grml is a live system (live CD) based on Debian. It includes a collection of GNU/Linux software especially for system administrators and users of texttools. It provides automatic hardware detection and its default shell is the zsh. You can use it e.g. as a rescue system, for analyzing systems/networks, or as a working environment. It is not necessary to install anything to a hard disk; you don't even need a hard disk to run it. Due to on-the-fly decompression, it includes more than 2 GB of software and documentation on the CD.
The sniffy project can trace/log the data of any pseudo terminal in the system. Due to the way the terminal works, such a terminal trace provides complete information of what happened on the terminal screen, and sniffy is able to display/replay this information. It consists of a kernel module able to connect/hook on the pseudo terminal, a program to display the contents of any pseudo terminal on the fly, a daemon process tracing the pseudo terminal content into the file, and a replay program to replay any stored pseudo terminal session.
Plash is a sandbox for running GNU/Linux programs with minimum privileges. It is suitable for running both command line and GUI programs. It can dynamically grant Gtk-based GUI applications access rights to individual files that you want to open or edit. This happens transparently through the Open/Save file chooser dialog box, by replacing GtkFileChooserDialog. Plash virtualizes the file namespace and provides per-process/per-sandbox namespaces. It can grant processes read-only or read-write access to specific files and directories, mapped at any point in the filesystem namespace. It does not require modifications to the Linux kernel.
Hardened Debian improves Debian GNU/Linux with high security and hardening features, hardened kernels and packages, DHKP, and other security related enhancements. It makes systems more difficult to compromise using common attacks such as race conditions, chroot jail escapes, and buffer overflows.