Agnix is a small, educational operating system kernel for i386, supporting 32-bit protected memory mode, paging, hardware switched tasks, memory tests, PCI bus, devices, PCI IRQ routing, RT timers, network protocols. It is available with all the source code and is fully compatible with the Linux kernel API.
The "EeePC-optimized Kernel for Ubuntu" project aims to produce a set of pre-compiled kernel packages that have been specially tailored to the EeePC's hardware and power usage, and to deliver these packages on a dedicated repository hosted by the author. Delivering these kernel packages over a Debian-style repository ensures that future updates and patches can be automatically downloaded to your EeePC as they're released. Current support is available for Ubuntu v8.04 (Hardy Heron) on the EeePC 700, 900, 900A, 901, 1000, and 1000H models.
Finnix is a small, self-contained, bootable Linux CD distribution ("LiveCD") for system administrators, based on Debian testing. You can use it to mount and manipulate hard drives and partitions, monitor networks, rebuild boot records, install other operating systems, and much more.
Fritz!WRT is a set of patches to make the OpenWRT trunk run on AVMs Fritz!Box. Much progress has been made in recent OpenWRT revisions in the AR7 port, but it's still not running on the Fritz!Box. The patches also have the potential to make the T-Com SpeedPort run, because its hardware is very similar to that of the Fritz!Box. There are patches for the bootloader, LED support, and watchdog support, as well as KGDB support.
HeavenOS is an original, alternative 32-bit operating system for Intel 80386 compatible processors. It is made with NASM (The Netwide Assembler), and is not intended to compare to modern operating systems, but to try to get the best features and discover better ways to do things. It is intended to be a simple and pratical platform for development, running with a small amount of code.
Hotplug2 is aimed at early Linux user space, i.e. initramfs or initrd, and possibly also at embedded devices (such as WRT-like routers) or very weak machines, such as 386/486. It connects to the uevent netlink socket and reads events. The application generally operates in two modes: dumb and smart.
Hotplug lets you plug in new devices and use them immediately. That means that users won't need to learn so much system administration, since the Linux system will at least partially autoconfigure itself. Initially, hotplug included support for USB and PCI (Cardbus) devices, and could automatically configure some common network interfaces. Updated versions include IEEE 1394 (Firewire/i.Link) support and can download firmware to USB devices that need it.