Operating System Projects

• Aegis/Exo-kernel (Massachusetts Institute of Technology)
  Group Members: Frans Kaashoek, Dawson Engler
  The Aegis kernel is built around the idea of an exo-kernel. An evolution from micro-kernels, exo-kernels export a virtual machine that securely multiplexes resourses among mutually distrusting spplications. The exo-kernel philosophy tries to export as few abstractions besides the basic hardware abstractions as possible, and to implement as little policy in the kernel as possible. Like SPIN, Aegis relies on techniques such as downloading code into the kernel to make the system fast.
• AIOS
  The AIOS project is aimed toward developing a new computer operating system based on artificial intelligence.
• Alpha Kernel (Carnegie Mellon University) Group Members
• Amoeba (Vrije Universiteit)
  Amoeba is a powerful micro-kernel-based system that turns a collection of workstations or single-board computers into a transparent distributed system. It has been in use in academia, industry, and government for about 5 years.
• Angel (City University of London)
  Angel is designed as a generic parallel and distributed operating system, although it is currently targeted towards a high-speed network of PCs. This model of computing has the dual advantage of both a cheap initial cost and also a low incremental cost. By treating a network of nodes as a single shared memory machine, using distributed virtual shared memory (DVSM) techniques, we have addressed both the needs for improved performance and provided a more portable and useful platform for our applications.
• Apertos (Sony Computer Science Lab)
• BE OS (Be, Inc.)
  Be is a new multithreaded, multiprocessor microkernel OS that has been designed from the ground for multimedia applications. It currently runs on the Intel and some PowerPC platforms. [ Everything I've heard about Be sounds really good. Everyone who uses it seems to be very impressed - Patrick ]
• BPMK
• BSD/OS (Berkeley Software Design, Inc.)
  BSD/OS is a commercial BSD 4.4-based UNIX operating system for the x86 PC. This is where many of the Berkeley CSRG people went after BSD UNIX research ended at Berkeley. A commercial-quality UNIX implementation with all of the bells and whistles one expects from a modern UNIX system. In some sense, a "let's finally make some money out of all of hard our work" project. Seems fair to me.
• C Executive and PSX (JMI Software Systems)
  C EXECUTIVE is a operating system kernel for embedded applications - providing a small, efficient, real-time software environment for programs written in C. C EXECUTIVE, as small as 5 KB in ROM space, is available on 8-, 16- and 32-bit CISC and RISC processors, providing the foundation for a common, corporate-wide, portable software strategy. PSX provides a single-user, single-group, subset of POSIX.1, with up to 32,000 preconfigured processes. PSX adds a substantial subset of the POSIX.1 system calls to the basic C EXECUTIVE kernel. Using these calls allows applications to migrate from POSIX-conformant UNIX platforms to board-level systems, or vice versa.
• Cache kernel (Stanford University Distributed Systems Group)
  Group Members: David Cheriton, Kenneth Duda
  The supervisor-mode component of the V++ operating system. The Cache Kernel caches operating system objects such as threads and address spaces just as conventional hardware caches memory data. User-mode application kernels handle the loading and write-back of these objects, implementing application-specific management policies and mechanisms.
• Chimera (Carnegie Mellon University)
  The Advanced Manipulators Laboratory, at Carnegie Mellon University, has developed the Chimera Real-Time Operating System, a next generation multiprocessor real-time operating system (RTOS) designed especially to support the development of dynamically reconfigurable software for robotic and automation systems. Version 3.0 and later of the software is already being used by several institutions outside of Carnegie Mellon, including university, government, and industrial research labs.
• Choices (University of Illinois, Urbana-Champaign)
  Choices is written as an object-oriented operating system in C++. As an object-oriented operating system, its architecture is organized into frameworks of objects that are hierarchically classified by function and performance. The operating system is customized by replacing subframeworks and objects. The application interface is a collection of kernel objects exported through the application/kernel protection layer. Kernel and application objects are examined through application browsers
• Chorus (Sun Microsystems)
  CHORUS is a family of open micro-kernel-based operating system components to meet advanced distributed computing needs in areas such as telecommunications, internetworking, embedded systems, realtime, "mainframe UNIX", supercomputing and high availability. The CHORUS/MiX multiserver implementations of UNIX allow to dynamically integrate part or all of standard UNIX functionalities and services in the\ above application areas.
• COSY (University of Karlsruhe, University of Paderborn)
  Group Members: Wolfgang Burke, Roger Butenuth, Sven Gilles
  Cosy is an operating system for highly parallel computers, with hundreds or thousands of processors. All parts of the system are designed to scale up with the number of processors, without any one becoming a bottleneck.
• EROS (University of Pennsylvania) Group Members
  EROS (Extremely Reliable Operating System) is a new operating system being implemented at the University of Pennsylvania. The system merges some very old ideas in operating systems with some newer ideas about scheduling and performance. The result is a small, secure, high-performance operating system that provides transparent orthogonal persistence coupled with microkernel-style critical paths, including a high performance IPC subsystem.
• Flux (University of Utah) Group Members
  The Flux Project's objective is to develop a nanokernel-based decomposed operating system that achieves high performance while retaining inter-component protection and rich functionality. Such a system will overcome the performance/protection and performance/functionality tradeoffs that thwart traditional micro-kernel-based operating systems. This objective includes integration of selected research results of others, and free distribution of an unencumbered and usable version of the entire system.
• FreeBSD
  FreeBSD is one of several free, monolithic BSD 4.4-lite derivative operating systems. It provides full UNIX support, including networking, X Windows, and almost all other normal UNIX services.
• Fox (Carnegie Mellon University) Group Members
  The objective of the Fox Project is to advance the art of programming-language design and implementation, and simultaneously to apply principles of programming languages to advance the art of systems building. The starting point for the work on language design and implementation is the Standard ML programming language.
• GLUnix (University of California, Berkeley)
  Group Members: Thomaas Anderson, Doug Ghormley, David Petrou, et al.
  Currently, modern workstation operating systems do not provide support for efficient distributed program execution in an environment shared with sequential applications. The goal of our research is to pool resources in a NOW to provide better performance for both parallel and sequential applications. To realize this goal, the operating system must support gang-scheduling of parallel programs, identify idle resources in the network, allow for process migration to support dynamic load balancing, and provide support for fast inter-process communication.
• Grasshopper (University of Sydney) Group Members
  Despite the fact that the basic idea behind orthogonal persistence is very simple, research groups are finding it extremely hard to develop scalable and efficient persistent stores. One of the major difficulties derives from the fact that persistence provides a fundamentally different model of computing from that supported by conventional operating systems. In this project we are investigating the requirements of an operating system to support persistence and propose to design and construct a new operating system, known as Grasshopper, which has explicit support for persistent systems.
• GUIDE
  Guide (Grenoble Universities Integrated Distributed Environment) is an object-oriented distributed operating system for the development and operation of distributed applications on a local area networks connecting workstations and servers. Guide is a joint project of Bull and the IMAG Research Institute (Universities of Grenoble), which have created the Bull-IMAG joint Research Laboratory. It also has strong links with the COMANDOS Esprit Project (Construction and Management of Distributed Open Systems) and the BROADCAST Esprit Basic Research project.
• Harmony (National Research Council of Canada)
  Harmony is a multitasking, multiprocessing operating system for realtime control, developed at the National Research Council to serve a need for a flexible system for realtime control of robotics experiments and for other applications of embedded systems where predictable temporal performance is a requirement. Harmony is extensible, configurable and portable, both across different target computers (typically assembled from single-board computers), and across different development hosts.
• Helios (Perihelion Distributed Software)
  Helios is a micro kernel operating system for embedded and multiprocessor systems. The operating system is modular in design and can scale from an embedded runtime executive up to a fully distributed operating system.
• Hive (Stanford University Flash Project) Group Members
  The Hive OS Team is designing an operating system that is able to operate effectively in a traditional supercomputer environment as well as in a general-purpose, multiprogrammed environment. The latter environment poses significant challenges since general-purpose environments typically contain large numbers of processes making many system calls and many small I/O requests.
• HURD (Free Software Foundation GNU Project)
  Related to: Mach
  The HURD is the operating system being developed by the Free Software Foundation as the basis for the GNU Project, which has already produced such well known tools as Emacs and GCC. The Hurd is a personality for the Mach micro-kernel which exports a bevy of services to the application. The Hurd will provide the standard UNIX interface, but should also be much more flexible than standard UNIX.
• Hurricane
  The Hurricane operating system is a hierarchically clustered operating system implemented on the Hector multiprocessor. Hierarchical clustering manages the system resources in clusters, using tight coupling within a cluster, and loose coupling across clusters. Distributed systems principles are applied by distributing and replicating system services and data objects to increase locality, increase concurrency, and to avoid centralized bottlenecks, thus making the system scalable.
• Inferno
  Inferno(tm) is a new network operating system and programming environment to deliver content in a rich environment of heterogenous networks, clients and servers. The Inferno system includes the Inferno kernel, the Limbo(tm) programming language, reference APIs that include interfaces for networking and graphics, network protocols, security and authentication, and various toolkits. Inferno was developed by members of the Computing Sciences Research Center of Bell Laboratories, the research arm of Lucent Technologies.
• ITRON
  ITRON (industrial TRON) is a real-time operating system specification for embedded systems. Many products have been developed based on the ITRON specifications. ITRON is a de-fact standard operating system specification in Japan for consumer applications.
• Kea (University of British Columbia)
  Group Members: Norm Hutchinson, Alistair Veitch, Peter Smith, et al.
  Kea is an operating system architecture designed to provide the applications running on top of it with the ability to dynamically replace parts of the system. Don't like your file-systems buffering policy? Write your own, the system will replace it for your application! Of course, there are lots of research and design issues over how we do this on a fine-grained scale, whilst maintaining system integrity and efficiency.
• KeyKOS
  KeyKOS is an operating environment for S/370 computers which provides a high level of security, reliability, performance, and productivity. It allows emulation of other environnzens such as VM, MVS, and POSIX. Development of KeyKOS ceased in 1990. Many of the ideas of this system have been carried forward into EROS
• L3 and L4
  Group Members: Jochen Liedtke
• Linux
  Group Members: Linus Torvalds and a Cast of Thousands
  Linux is a freely-distributable implementation of UNIX for 80386, 80486 and Pentium machines. It supports a wide range of software, including X Windows, Emacs, TCP/IP networking (including SLIP/PPP/ISDN), and the works. Ports to non-x86 machines such as the Alpha and SPARC also exist. This is one rocking project.
• Lites
  Related to: Mach
  Lites is a 4.4 BSD Lite based server and emulation library that provides free unix functionality to a Mach based system. Lites provides binary compatibility with 4.4 BSD. NetBSD (0.8, 0.9, and 1.0), FreeBSD (1.1.5 and 2.0), 386BSD, UX (4.3BSD) and Linux on the i386 platform. It has also been ported to the pc532, and PA-RISC. Preliminary ports to the R3000 and Alpha processors have also been made.
• Lynx (Lynx Real-time Systems)
  LynxOS is a proprietary UNIX-like real-time operating system. LynxOS looks and feels like UNIX from the user/programmer point of view. It was developed from the ground-up with high performance, deterministic hard real-time response in mind. Although LynxOS is conformant with POSIX 1003.1 it is not derived from any AT&T;/USL/Novell source code. The OS is in effect a complete re-implementation of UNIX from a real-time perspective.
• Mach (Carnegie Mellon University)
  Mach is one of the giants in the operating systems research community. Originally started at CMU, Mach has become the basis for many research systems. Although work on Mach at CMU has largely stopped except real-time work and multi-server work, many other groups are still using Mach as the basis for research.
• Mach at OSF (OSF Research Institute)
  Related to: Mach
  The OSF Research Institute is using the Mach technology started at CMU and is using it as the basis for several areas of research, including operating systems for parallel machines, trusted object-oriented kernels, and other OS research areas.
• Mach-US (Carnegie Mellon University)
  Related to: Mach
  The Mach-US system is an OS developed as part of the CMU MACH project. It is comprised of a set of servers, each of which supports orthogonal system services. For example, instead of one server supplying all of the system services as under the Mach BSD4.3 single server (UX), the Mach Multiserver (Mach-US) has several servers: a task server, a file server, a tty server, an authentication server, a network server, etc. It also has and emulation library that is mapped dynamically into each user process, and uses the system servers to support the application programmers interface (API) of the UNIX operating system.
• MacOS (Apple Computer Corporation)
  Related to: Rhapsody
• Maruti (University of Maryland) Group Members
  Maruti is a time-based operating system research project at the University of Maryland. With Maruti 3.0, we are entering a new phase of our project. We have an operating system suitable for field use by a wider range of users, and we are embarking on the integration of our time-based, hard real-time technology with industry standards and more traditional event-based soft- and non-real-time systems.
• Masix (Blaise Pascal Institute MASI Laboratory)
  Group Members: Rémy Card, Franck Mével, Julien Simon
  Related to: Mach
  Masix is a distributed operating system, based on the Mach micro-kernel, currently under development at the MASI Laboratory. Its primary goal is the simultaneous execution of multiple personalities, in order to run concurrently on a same workstation applications from the Unix, DOS, OS/2 and Win32 worlds. Furthermore, Masix pools the resources of a workstation local area network, independently from the personalities that run on each node. Masix also provides distributed services to the personalities.
• Merlin (University of Sao Paulo)
  An object-oriented, reflective operating system based on the Self programming language
• MetaOS (University of Victoria)
  MetaOS is an object-oriented system model, based on meta-levels, meta-spaces, meta-objects, and meta-interfaces, that allows applications to securely customize their run-time environment on the fly. Furthermore, it allows applications to share customizations with other applications, allows different types of security schemes to be implemented, and permits secure, remote troubleshooting of software.
• MOSIX (Hebrew University, Jerusalem, Israel) Group Members
  A solution to the NOW problem is now available in the form of a multicomputer operating system enhancements, called MOSIX. MOSIX is an enhancement of UNIX which allows users to use the resources of a NOW configuration, without any change to the application level. By using transparent, dynamic process migration algorithms, MOSIX enhances the network services, i.e. NFS, TCP/IP, of UNIX, to the process level, by supporting load balancing and a dynamic work distribution (leveling) in clusters of homogeneous computers.
• MTOS
• Mungi (University of New South Wales)
  A new operating system based on a single, flat virtual address space, orthogonal persistence, and a strong but unintrusive protection model.
• Nemesis (University of Cambridge, UK)
  Pegasus has produced an entirely new operating system, whose design is geared to support of high-performance applications which require a consistent quality of service (QoS), such as those which use multimedia. This operating system, called Nemesis, currently runs on a number of platforms including Intel, Alpha (21064 and 21164) and StrongARM.

  Nemesis is a single-address-space system, with an extremely light-weight kernel ('Nemesis Trusted Supervisor Code', or NTSC), and strong emphasis on performing operating system functions in the user's domain (thus avoiding the need for expensive protection regime changes).

• NetBSD Group Members
  NetBSD is one of two free, monolithic BSD 4.4-lite derivative operating systems. It provides full UNIX support, including networking, X Windows, and almost all other normal UNIX services. Unlike many other free UNIX implementations, NetBSD has also been ported to a large variety of hardware platforms.
• Oberon
  Oberon is a freely distributable OS written in the Oberon language in the Pascal-Modula tradition, developed by Niklaus Wirth and Juerg Gutknecht at the Institute for Computer Systems at the Swiss Federal Institute of Technology in Zurich (ETHZ). The most recent development of it is called Oberon System 3. It is available as Native Oberon for Intel-based machines which is self-contained and makes no use of any alien software layer. In addition, ports exist for all flavors of Windows: 3.1, 3.11, 95 and NT, as well as for Linux and for Macintosh.
• Opal (University of Washington)
  Related to: Mach
  Opal is a single-address-space operating system for 64-bit architectures. All Opal threads execute with a single global address space. The existence of a single address space simplifies sharing of complex (pointer-rich) data among cooperating applications, as well as persistent storage of that data, because pointers have the same meaning to all threads for potentially all time. Opal provides protection in the single address space; each thread executes within a protection domain that defines which pages it has the right to access.
• OpenBSD
  Yet another group pushing a free BSD-Lite derivative. This group splintered off of the NetBSD project, for reasons unclear to me, although I'd guess perhaps becuase NetBSD wasn't pushing out regular releases fast enough, and FreeBSD wasn't supporting non-x86 platforms. The splintering of BSD people has effectively killed any chance of BSD beating Linux, expecially given the good work porting Linux to other platforms.
• OpenSTEP (Apple Computer Corporation)
  Related to: Mach
  Steve Jobs' brain child after Apple, all that is left of NeXT is the remarkably good NeXTSTEP/OPENSTEP Operating System, a mach-based mostly UNIX with a very good user interface and programmer environment. It's now available for the x86 PC, and many people really like it. OpenSTEP may be the basis of the next Mac OS, Rhapsody.
• OS9 (Microware Systems Corporation)
  OS-9 is a real-time, multiuser, multitasking operating system developed by Microware Systems Corporation. It is modular, allowing new devices to be added to the system simply by writing new device drivers, ]or if a similar device already exists, by simply creating a new device descriptor. All I/O devices can be treated as files, which unifies the I/O system. In addition, the kernel and all user programs are ROMable.
• OSE
  OSE is a full-featured family of high quality, reliable and high performance real-time operating systems from Enea OSE Systems, Sweeden. There is an OSE kernel for every need, from OSE Basic (for Z80, i8051 and others) up to OSE Delta (for M68k, PPC and others). OSE Delta is also the first RTOS to be certified according to the software quality standard IEC 1508. OSE Delta supports runtime configuation, runtime program loading, multi-CPU systems and TCP/IP.
• Paramecium
  This kernel uses an object-based software architecture which together with instance naming, late binding and explicit overrides enables easy reconfiguration. Determining which components are allowed to reside in the kernel address space is up to a certification authority or one of its delegates. These delegates may include validation programs, correctness provers, and system administrators. The main advantage of certifications is that it can handle trust and sharing in a non-cooperative environment.
• PEACE (Process Execution And Communication Environment) (GMD FIRST)
  PEACE is a family of operating systems with a truly object-oriented design developed at GMD FIRST. Emphasis is laid on subjects as performance, configurability and portability. It is the native operating system for the MANNA computer, a massively parallel computer facilitating a high-performance interconnection network. Ports to SunOS, FreeBSD and Parix were made and expand the scope of this system to other parallel computers as well as to workstation networks.
• Plan 9 (Bell Labs Computing Science Research Center)
  Plan 9 is a new computer operating system developed at Bell Labs. It is a distributed system. In the most general configuration, it uses three kinds of components: terminals that sit on users' desks, file servers that store permanent data, and CPU servers that provide faster CPUs, user authentication, and network gateways. One of the interesting facets of Plan 9 is that it exports a file-system interface to essentially all system services.
• Protection and Sharing through Shared Libraries (University of Notre Dame)
  Group Members: Arindam Banerji
  Protected Shared Libraries (PSLs) are based on the observation that shared libraries, with some modifications, could be used to implement user-level OS services with adequate protection and many degrees of sharing. Furthermore the dynamic nature of loadable shared libraries can be extended to provide a high degree of flexibility in the implementation of user-level services. Protected Shared Libraries add two different dimensions to the usual notion of shared libraries - protection domains and multiple forms of sharing through Shared Address Libraries.
• Puma and relatives (Sandia National Laboratory)
  The Puma operating system targets high-performance applications on tightly coupled distributed memory architectures. It is a descendant of SUNMOS.
• QNX
  A micro-kernel, distributed, real-time, fault-tolerant, POSIX-certified OS for the x86. QNX adopts the approach of implementing an OS with a 10 Kbyte micro-kernel surrounded by a team of optional processes that provide higher-level OS services. QNX is fully distributed, with all system interfaces network transparent. QNX has successfully been used in tiny ROM-based embedded systems and in several-hundred node distributed systems.
• Rhapsody (Apple Computer Corporation)
  Related to: MacOS
  Rhapsody is the code name for a new operating system from Apple Computer, Inc., designed to complement Mac OS by providing a variety of high-end solutions. The Rhapsody operating system, available on both PowerPC and Pentium-class processors, provides preemptive multitasking, protected memory, and other modern operating system features.
• Roadrunner
  In traditional operating systems, input/output (I/O) subsystems implement a push-pull environment that provides system calls to allow user applications to pull data from or push data to a device. An important set of applications make combined use of push-pull to implement simple streaming, i. e. data is moved from one device to another with no transformations. Using push-pull I/O to implement these applications does not provide maximum performance. This work proposes a kernel design optimized for simple streaming applications. The Roadrunner operating system is being developed specifically to implement multiple, concurrent, high-speed speed data streams with Quality-of-Service (QOS) parameters.
• Real-Time Mach Project (Carnegie Mellon University) Group Members
  Related to: Mach
  Real-Time Mach is a research prototype real-time operating system intended for use as a vehicle for doing real-time systems research. The system is being developed by the ART Project in the School of Computer Science, Carnegie Mellon University.
• RTEMS (Redstone Military Arsenal)
  RTEMS is a real-time operating system for embedded computer systems with the following features:
  • support for homogeneous and heterogeneous multiprocessor systems
  • event-driven, priority-based, preemptive scheduling
  • optional rate monotonic scheduling
  • intertask communication and synchronization
  • responsive interrupt management
  • dynamic memory allocation
• RTMX O/S
  Group Members: RTMX Incorporated
  RTMX is a commercial, BSD 4.4-derived, real-time system that offers POSIX 1003.4 real-time programming support with user tunability along with the standard UNIX functionality of BSD networking, X windows, and a full C development environment.
• RTX
  Group Members: Mike Podanoffsky
  RTX is a very small, very fast real time executive that utilizes signals and queuing as a basis for managing and scheduling tasks. It becomes very easy to support multiple processors, communication channels, and to synchronize processes. RTX is completely free, but it is not public-domain software. If you decide to use the software, you may receive an automatic license to do so even in commercial products, if you provide adequate, reasonable credit to its developer.
• Scout (University of Arizona) Group Members
  The Scout project is a new operating system project that aims to build a fast, customizable operating system for networked systems by looking at novel ways to structure and construct operating systems. The Scout operating system is designed around the path, which is how data flows between end-points in a system. Paths are primary objects to which resources are allocated in Scout. The Scout system is also exploring new compiler technologies for system design and implementation, based on the insight that extensible operating systems are worthless if no one can build or extend them.
• Sombrero (Arizona State University)
• SPACE (University of California, Santa Barbara)
  Group Members: John Bruno, Dave Probert
  SPACE is an approach to operating systems which uses multiple protection domains rather than a single kernel to provide operating system services. Multiple instances of fundamental paradigms, such as threads and virtual memory, can coexist, since they are implemented as applications code. All that is left in what was the operating system kernel is a set of mechanisms to implement the protection domains. In SPACE these mechanisms.can be replaced as needed by the application to provide a fundamental level of extensibility not available in other adaptive operating systems.
• SPIN (University of Washington) Group Members
  SPIN is one of several research systems that aims toward run-time flexibility and specialization using techniques like type-safe languages and dynamic code generation to make a fast, dynamic, flexible system. It is an extensible operating system micro-kernel that supports the dynamic adaptation of system interfaces and implementations through direct application control, while still maintaining system integrity and inter-application isolation.
• Spring Real-Time Project (University of Massachsetts, Amherst) Group Members
  The Spring kernel has been designed and implemented to support/provide predictability, on-line dynamic guarantees, atomic guarantees, end-to-end scheduling and resource reservations. It utilizes a micro-kernel design for multiprocessor architectures and provides an interface to remote processes, support for distributed shared memory, and predictable low level communication. The kernel exists as a component of Spring's integrated environment. This environment extracts significant semantic information and this information is used at runtime to support flexibility. (ed: This is not the same as the Spring OS from Sun, which unfortunately has the same name.)
• Spring System (Sun)
  Sun's new research kernel. Spring is a highly modular, object-oriented operating system, which is focused around a uniform interface definition language. Spring is intrinsically distributed, with all system interfaces being accessible both locally and remotely.
• Sprite (University of California, Berkeley)
  Sprite was a UNIX-like distributed operating system developed at Berkeley which ran on a number of different machines, and had a number of interesting features, such as load-balancing, a high-speed, aggressively-caching, distributed file-system, and a fast log-structured local file-system. Research on Sprite per-se come to an end, although various former members of the Sprite group are carrying on aspects of the original Sprite research.
• Sting
  Sting is an experimental operating system designed to serve as an efficient customizable substrate for modern programming languages. The base language used in our current implementation is Scheme, but Sting's core ideas could be incorporated into any reasonably high-level language. The ultimate goal in this project is to build a unified programming environment for parallel and distributed computing.
• Sumo (Lancaster University)
  Related to: Chorus
  Over the past few years members of the SUMO team have been designing and implementing a microkernel based system with facilities to support distributed real-time and multimedia applications and ODP based multimedia distributed application platforms. We are interested in both communications and processing support for distributed real-time/ multimedia applications in end systems, and believe that such applications require thread-to-thread real-time support according to user supplied quality of service (QoS) parameters.
• Synthesis (Columbia University)
  Group Members: Henry Massalin
  The Synthesis kernel was one of the first modern operating system projects to use run-time code generation (which Massalin called code synthesis) and fine-grained scheduling to construct a system that responded quickly and dynamically to high-speed devices. The main "draw-back" of Synthesis was that it was written is 68000 macro-assembler. Synthesis has influnced most of the modern extensible research operating systems, including SPIN, Aegis, Scout, and Synthetix.
• Synthetix (Oregon Graduate Institute)
  Group Members: Andrew P. Black, Charles Consel, Calton Pu, et al.
  The Synthetix project is investigating the application of a technique called incremental specialization, a combination of fine-grain modularity and dynamic code generation, to create operating systems which are both highly modular and high-performance. Incremental specialization takes advantage of particular circumstances, not just at compile time, but also at load time and run time, to make specialized optimizations.
• Tao Operating System (Tao Systems) Group Members
  Tao is a radical commercial operating system or run time module offering all of the features required for the building of leading edge, cost driven, embedded consumer electronics (single and multi-processor). It is available on a broad range of processors both as a stand alone OS and co-existing with host operating systems.
• Tigger (Trinity College Dublin) Group Members
  The Tigger project is developing a framework for the construction of a family of distributed object-support platforms suitable for use in a variety of distributed applications ranging from embedded soft-real time systems to concurrent engineering frameworks. Customisability, extensibility and portability are put forward as the way to handle diversity and are thus the core design goals in Tigger.
• Tornado (University of Toronto)
  Tornado is a new operating system being developed for the NUMAchine that addresses NUMA programming issues using novel approaches, some of which were developed for our previous operating system Hurricane. Tornado uses an object-oriented, building block approach that allows applications to customize policies and adapt them to their performance needs. For research purposes, we intend to tune Tornado for applications with very large data sets that typically do not fit in memory and hence have high I/O demands. We also intend to provide applications with an operating environment that provides predictable performance behavior to allow performance tuning and to allow the application to appropriately parameterize its algorithms at run-time.
• TUNES Group Members
  Tunes is a project to replace existing Operating Systems, Languages, and User Interfaces by a completely rethough Computing System, based on a correctness-proof-secure higher-order reflective self-extensible fine-grained distributed persistent fault-tolerant version-aware decentralized (no-kernel) object system. We want to implement such a system because we know all these are required for the computing industry to compete fairly, which is not currently possible. Even if Tunes itself does not become a world-wide OS, we hope the TUNES experience can speed up the appearance of such an OS that would fulfill our requirements.
• Vino (Harvard University)
  VINO's key attributes are reusability of kernel mechanisms by user-level applications, application-directed kernel policy, and an access-method paradigm similar to that used by database management systems. The goal of VINO is to reduce the size of conventional operating systems by leaving the definition of complex kernel policies with applications. Additionally, the VINO system will provide improved performance for applications, since they can retain more control over their resources. Finally, VINO is designed to enable the development of new applications, such as real-time video, that require explicit control of system resources.
• VSTa
  VSTa is an experimental kernel which attempts to blend the design of a micro-kernel with the system organization of Plan 9. The result is a small privileged kernel running user-mode tasks to provide system services such as device drivers, file systems, and name registry. Like Plan 9, each service provides a file system-like interface.
• VxWorks (Wind River Systems)
  VxWorks(R) is the premier development and execution environment for complex real-time and embedded applications on a wide variety of target processors. Three highly integrated components are included with VxWorks: a high performance scalable real-time operating system which executes on a target processor; a set of powerful cross-development tools which are used on a host development system; and a full range of communications software options such as Ethernet or serial line for the target connection to the host.
• x-kernel (University of Arizona)
  The x-kernel is an object-based framework for implementing network protocols. It defines an interface that protocols use to invoke operations on one another (i.e., to send a message to and receive a message from an adjacent protocol) and a collection of libraries for manipulating messages, participant addresses, events, associative memory tables (maps), threads, and so on.