Visopsys is an alternative operating system for PC compatible computers. Under development since late 1997, this system is small, fast, and open source. It features a simple but functional graphical interface, real preemptive multitasking, and virtual memory. Though it attempts to be compatible in a number of ways, Visopsys is not a clone of any other operating system. You can demo the distribution from a "live" CD, USB stick, or floppy disk.
amforth is an extendible command interpreter for the Atmel AVR ATmega microcontroller family. It has a turnkey feature for embedded use as well. It does not depend on a host application. The command language is an almost compatible ANS94 forth with extensions. It needs less than 8KB code memory for the base system. It is written in assembly language and forth itself.
QP is a family of lightweight software frameworks for building responsive and modular real-time embedded applications as systems of cooperating, event-driven active objects (actors). The QP family consists of QP/C, QP/C++, and QP-nano frameworks, which are all strictly quality controlled, superbly documented, and commercially licensable. The behavior of active objects is specified in QP by means of hierarchical state machines (UML statecharts). The frameworks support manual coding of UML state machines in C or C++ as well as automatic code generation by means of the free QM modeling tool. All QP frameworks can run on bare-metal MCUs, completely replacing a traditional RTOS. Ports and ready-to-use examples are provided for all major CPUs, such as ARM Cortex-M, ARM7/9, MSP430, C28x, C55x, RX, R8C, AVR32, AVRMega, PIC24/dsPIC, as well as Arduino and mbed. QP/C and QP/C++ can also work with a traditional OS/RTOS, such as: POSIX (Linux, QNX), Windows, VxWorks, ThreadX, and uC/OS.
DMAring demonstrates a novel generic network interface card driver architecture which works in hybrid interrupt-polling mode to deliver superior real-time performance on Linux, Red Hat Linux, or Linux-RTAI-LXRT (a real-time co-kernel for Linux with user level extension). Existing Linux drivers saturate the CPU at a much lower packet rate than the maximum possible wire line packet rate, but this driver allows vanilla network cards to be used for high speed packet capturing.
ReactOS is an advanced operating system providing a ground-up implementation of a Microsoft Windows XP/Windows Server 2003-compatible operating system. It aims to achieve complete binary compatibility with both applications and device drivers meant for XP and NT 5.2 operating systems by using a similar architecture and providing a complete and equivalent public interface. Written completely from scratch, ReactOS is not a Linux based system, and shares none of the UNIX architecture.
HelenOS is a microkernel-based multiserver operating system designed from scratch. By decomposing the operating system functionality into tens of isolated but intensively communicating userspace servers, it provides a computing environment that has several virtues such as flexibility, increased robustness, well defined explicit interfaces, and smaller complexity of individual components. HelenOS does not aim to be another clone of Unix or some other legacy system and is not POSIX-compliant (even though it may seem POSIX-similar at times). Instead, the goal has been to design it according to what is the most elegant and right thing to do. What makes HelenOS unique among the other multiserver operating systems is its multiplatform and multiprocessor microkernel. It will run on seven different processor architectures ranging from a 32-bit uniprocessor little-endian ARMv4 to a 64-bit multicore big-endian UltraSPARC T1.
The Web10G project (a follow-on from Web100) was created to produce a complete host-software environment that will run common TCP applications at 100% of the available bandwidth, regardless of the magnitude of a network's capability. Web10G has endowed TCP with better instrumentation. This instrumentation is the foundation for both the TCP autotuning performed in process-level code and the process-level tools designed to locate bottlenecks within the following major subsystems: the sending application, the sending OS, the Internet path, the receiving OS, and the receiving application. Measurement tools have also been built on this instrumentation to display performance indicators to end-users, as well as provide internal diagnostics for network and system administrators.