FreeNOS is an experimental microkernel operating system for learning purposes. The system is very experimental, yet it currently supports virtual memory, simple task scheduling, and interprocess communication (IPC). It currently contains support for a few devices, including VGA, keyboard, i8250 serial, ATA drives, and PCI controllers. FreeNOS has an experimental implementation of several filesystems, such as the virtual file system, procfs, tmpfs, linnfs, and ext2fs. Current application libraries include libposix, libc, libteken (terminal emulation), and libexec (executable formats). All source code has been documented with Doxygen tags. It has been tested on recent versions of Qemu, VMWare, VirtualBox, Bochs, and bare hardware.
slakbootEBS is a software development kit for the automated creation of bootable embedded systems based on Slackware and Busybox. The focus is on i486 and ARM systems that use compact flash devices (handhelds and PC104 type boards). The distribution consists of a primary archive with tools, scripts, and documentation, and additional archives for the i486 and PXA250 binary components.
Stem Desktop is a minimalistic Debian desktop for low-end hardware with limited memory (166Mhz / less than 64M). The goal is to find programs that have the smallest possible memory footprint. After installing *.deb packages on top of clean Debian, the desktop is ready to accept graphical logins.
The deepOfix Mail Server makes it possible for organizations with minimal technical expertise to have robust server infrastructure. deepOfix offers unprecented ease of use, doesn't require prior GNU/Linux experience and is backed by a full-time development and support team. deepOfix features LDAP-based directory services for user account management, email delivery, distribution lists, and addressbooks. It also includes built in tools for spam and virus control, webmail, and fetching email.
Kerrighed is a Single System Image operating system (SSI) for clusters. It offers the view of a unique SMP machine on top of a cluster of standard PCs. The goals are high performance of applications, high availability of the cluster, efficient resource management, high customizability of the operating system, and ease of use. It is implemented as an extension to Linux operating system (a set of Linux modules and a small patch to the kernel).
INSERT (the Inside Security Rescue Toolkit) aims to be a multi-functional, multi-purpose disaster recovery and network analysis system. It boots from a credit card-sized CD-ROM and is basically a stripped-down version of Knoppix. It features good hardware detection, fluxbox, emelfm, links-hacked, ssh, tcpdump, nmap, chntpwd, and much more. It provides full read-write support for NTFS partitions (using ntfs-3g), and the ClamAV virus scanner (including a fairly recent signature database and a GUI). It provides partition handling with gParted and also has a network boot facility.
eyeOS is a Web desktop environment, commonly known as a Web OS or Web Office. The basic system comes with some office and PIM applications, and the complete eyeOS software database can be found at eyeApps.org and in the public server. More information can be found at the forums and in the screenshots section.
Nexenta is a complete GNU-based operating system built on top of the OpenSolaris kernel and runtime. The Debian system is used for software distribution and packaging to glue the numerous pieces together. However, Nexenta is not currently part of the Debian Project, nor are its packages present in the Debian database. It includes Apache, MySQL, Perl, Python, PHP, Firefox, Evolution, a software update manager, Synaptic package manager, Gaim, Abiword, administration and development utilities, editors, graphics, GNOME, interpreters, libraries, and much more.