In computer science, a microkernel is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, thread management, and inter-process communication (IPC).
Mach is a kernel developed at Carnegie Mellon University by Richard Rashid and Avie Tevanian to support operating system research, primarily distributed and parallel computing. Mach is often considered one of the earliest examples of a microkernel. However, not all versions of Mach are microkernels. Mach's derivatives are the basis of the operating system kernel in GNU Hurd and of Apple's XNU kernel used in macOS, iOS, iPadOS, tvOS, and watchOS.
Computer operating systems (OSes) provide a set of functions needed and used by most application programs on a computer, and the links needed to control and synchronize computer hardware. On the first computers, with no operating system, every program needed the full hardware specification to run correctly and perform standard tasks, and its own drivers for peripheral devices like printers and punched paper card readers. The growing complexity of hardware and application programs eventually made operating systems a necessity for everyday use.
L4 is a family of second-generation microkernels, used to implement a variety of types of operating systems (OS), though mostly for Unix-like, Portable Operating System Interface (POSIX) compliant types.
Meiko Scientific Ltd. was a British supercomputer company based in Bristol, founded by members of the design team working on the Inmos transputer microprocessor.
The development of a hobbyist operating system is one of the more involved and technical options for a computer hobbyist. The definition of a hobby operating system can sometimes be vague. It can be from the developer's view, where the developers do it just for fun or learning; it can also be seen from the user's view, where the users are only using it as a toy; or it can be defined as an operating system which doesn't have a very big user base.
XNU is the computer operating system (OS) kernel developed at Apple Inc. since December 1996 for use in the Mac OS X operating system and released as free and open-source software as part of the Darwin OS, which, in addition to being the basis for macOS, is also the basis for Apple TV Software, iOS, iPadOS, watchOS, visionOS, and tvOS.
Jochen Liedtke was a German computer scientist, noted for his work on microkernel operating systems, especially in creating the L4 microkernel family.
Spring is a discontinued project in building an experimental microkernel-based object-oriented operating system (OS) developed at Sun Microsystems in the early 1990s. Using technology substantially similar to concepts developed in the Mach kernel, Spring concentrated on providing a richer programming environment supporting multiple inheritance and other features. Spring was also more cleanly separated from the operating systems it would host, divorcing it from its Unix roots and even allowing several OSes to be run at the same time. Development faded out in the mid-1990s, but several ideas and some code from the project was later re-used in the Java programming language libraries and the Solaris operating system.
The RC 4000 Multiprogramming System is a discontinued operating system developed for the RC-4000 minicomputer in 1969. For clarity, this article mostly uses the term Monitor.
In computer science, a single address space operating system is an operating system that provides only one globally shared address space for all processes. In a single address space operating system, numerically identical logical addresses in different processes all refer to exactly the same byte of data.
In computer science, hierarchical protection domains, often called protection rings, are mechanisms to protect data and functionality from faults and malicious behavior.
SYmbiosis Multitasking Based Operating System (SymbOS) is a multitasking operating system for Zilog Z80-based 8-bit computer systems.
Gernot Heiser is a Scientia Professor and the John Lions Chair for operating systems at UNSW Sydney, where he leads the Trustworthy Systems group (TS).
Symobi is a proprietary modern and mobile real-time operating system. It was and is developed by the German company Miray Software, since 2002 partly in cooperation with the research team of Prof. Dr. Uwe Baumgarten at the Technical University of Munich. The graphical operating system is designed for the area of embedded and mobile systems. It is also often used on PCs for end users and in the field of industry.
The kernel is a computer program at the core of a computer's operating system and generally has complete control over everything in the system. The kernel is also responsible for preventing and mitigating conflicts between different processes. It is the portion of the operating system code that is always resident in memory and facilitates interactions between hardware and software components. A full kernel controls all hardware resources via device drivers, arbitrates conflicts between processes concerning such resources, and optimizes the utilization of common resources e.g. CPU & cache usage, file systems, and network sockets. On most systems, the kernel is one of the first programs loaded on startup. It handles the rest of startup as well as memory, peripherals, and input/output (I/O) requests from software, translating them into data-processing instructions for the central processing unit.
An embedded hypervisor is a hypervisor that supports the requirements of embedded systems.
Phantom OS is an orthogonally persistent managed code general-purpose operating system. It is based on a concept of persistent virtual memory, and executes bytecode in a virtual machine. It is one of a few OSes not based on classic concepts of Unix-like systems. Phantom is based on the principle that "Everything is an object", in contrast to the Unix-like approach of "Everything is a file".
Genode is a free and open-source software operating system (OS) framework consisting of a microkernel abstraction layer and a set of user space components. The framework is notable as one of the few open-source operating systems not derived from a proprietary OS, such as Unix. The characteristic design philosophy is that a small trusted computing base is of primary concern in a security-oriented OS.
