User-Mode Linux lets you run Linux inside Linux. It is a safe, secure way of running Linux versions and Linux processes. Run buggy software, experiment with new Linux kernels or distributions, and poke around in the internals of Linux, all without risking your main Linux setup. User-Mode Linux gives you a virtual machine that may have more hardware and software virtual resources than your actual, physical computer. You can assign your virtual machine only the hardware access you want it to have. With properly limited access, nothing you do on the virtual machine can change or damage your real computer or its software.
VIA High Speed Serial is a little kernel module (1 KB) which enables high speed serial port modes of VIA VT82C686A or VT82C686B southbridge-equipped motherboards. Basically, this is developed for ISDN-TAs, which at least in europe are constrained by the normal serial port speed of 115200 bit/s. With this module, you can use the serial port at 230400 bit/s so that you can get the full 128000 bit/s from ISDN-TA. The module has been tested with both 686A and 686B chipsets. Functionality is the same as with SHSMOD patches, but you don't have to patch the serial port driver.
The video4linux loopback device is a device driver which generates video pipes. It allows a user program to feed a video stream to another as if it were coming from an actual video device. It can be used for video filters, or for realtime viewing of the output of the "motion" program.
WinDriver automates and simplifies the development of user-mode Linux device drivers for PCI, CardBus, ISA, PMC, PCI-X, PCI-EXPRESS, and CompactPCI as well as USB 1.1/2.0. No internal OS knowledge or kernel level programming is required. It supports kernel 2.0.31 and above, including embedded Linux, x86 and PowerPC processors, and any 32-bit development environment supporting C or Delphi. Applications are source code compatible across Windows 98/Me/NT/2000/XP/XP Embedded/Server 2003/CE, Linux, Solaris, and VxWorks.
The Yoke driver provides transparant mirroring between disk partitions and other block devices (such as loop and nbd). It differs from the kernel RAID0 facility in that it is a virtual device with no interface of its own. To start mirroring one device to another requires no prior setup, just "yadd /dev/yd0 yet_another_device" and go. The yet_another_device will become another facet of the existing mirror and you can still read and write to it perfectly normally, with the difference that all changes will be seen and reflected in/from all the other mirror facets.
Keepalived for LVS aims to add a strong and robust keepalive facility to the Linux Virtual Server project. This project is written in C with multilayer TCP/IP stack checks. It implements a framework based on three family checks: Layer3, Layer4, and Layer5. This framework gives the daemon the ability of checking a LVS server pool states.When one of the servers in the LVS server pool is down, keepalived informs the Linux kernel via a setsockopt call to remove this server entry from the LVS topology. In addition, it implements a VRRPv2 stack to handle director failover.
Linux is a clone of the Unix kernel, written from scratch by Linus Torvalds with assistance from a loosely-knit team of hackers across the Net. It aims towards POSIX and Single UNIX Specification compliance. It has all the features you would expect in a modern fully-fledged Unix kernel, including true multitasking, virtual memory, shared libraries, demand loading, shared copy-on-write executables, proper memory management, and TCP/IP networking.