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NuKernel
NuKernel is a microkernel that was developed at Apple Computer during the early 1990s. It was the basis for the Copland operating system. It was written from scratch and designed using concepts from the Mach 3.0 microkernel, with extensive additions for soft real-time scheduling to improve multimedia performance. Only one NuKernel version was released, with a Copland alpha release. Development ended in 1996 with the cancellation of Copland. The External Reference Specification (ERS) for NuKernel is contained in its entirety in its patent. The one-time technical lead for NuKernel, Jeff Robbin, was one of the leaders of iTunes and the iPod. Apple's NuKernel is not the microkernel in BeOS, nukernel. See also *XNU, the microkernel in Mac OS X macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac comput ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jeff Robbin
Jeffrey L. Robbin is an executive and software engineer at Apple, Inc. He developed the SoundJam music player software, which was acquired by Apple in 2000. There, he created iTunes, and was "closely involved" with the iPod's development. In 2011, ''Bloomberg'' reported that he was leading development of an Apple television set, a device rumored in Steve Jobs's autobiography. As of 2018, he led the Apple Music product and engineering teams. Early life Robbin was born in Chicago. He took computer science courses as an undergraduate, and later obtained an MBA. Career While pursuing an MBA, Robbin joined Apple in 1992. There, he worked on Copland, Apple's troubled operating system project, alongside fellow software engineer Bill Kincaid. Robbin and Kincaid both left Apple in early 1997; Kincaid joined a startup, while Robbin went on to create several Mac utilities which were distributed by Casady & Greene. One of these utilities was Conflict Catcher, a system extension for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copland (operating System)
Copland is an operating system developed by Apple Inc., Apple for Macintosh computers between 1994 and 1996 but never commercially released. It was intended to be released with the name System 8, and later after changing their naming style, Mac OS 8. Planned as a modern successor to the aging System 7, Copland introduced memory protection, protected memory, Computer multitasking, preemptive multitasking, and several new underlying operating system features, while retaining compatibility with existing Mac applications. Copland's tentatively planned successor, codenamed Gershwin, was intended to add more advanced features such as application-level multithreading (computer architecture), multithreading. Development officially began in March 1994. Over the next several years, previews of Copland garnered much press, introducing the Mac audience to operating system concepts such as object orientation, crash-proofing, and multitasking. In August 1995, David Nagel, a senior vice preside ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BeOS
BeOS is a discontinued operating system for personal computers that was developed by Be Inc. It was conceived for the company's BeBox personal computer which was released in 1995. BeOS was designed for multitasking, multithreading, and a graphical user interface. The OS was later sold to OEMs, retail, and directly to users; its last version was released as freeware. Early BeOS releases are for PowerPC. It was ported to Macintosh, then x86. Be was ultimately unable to achieve a significant market share and ended development with dwindling finances, so Palm acquired the BeOS assets in 2001. Enthusiasts have since created derivate operating systems including Haiku, which will retain BeOS 5 compatibility as of Release R1. Development BeOS is the product of Apple Computer's former business executive Jean-Louis Gassée, with the underlying philosophy of building a "media OS" capable of up-and-coming digital media and multi-processors. Development began in the early 1990s, initially ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IPod
The iPod is a series of portable media players and multi-purpose mobile devices that were designed and marketed by Apple Inc. from 2001 to 2022. The iPod Classic#1st generation, first version was released on November 10, 2001, about months after the Macintosh version of iTunes was released. Apple sold an estimated 450 million iPod products as of 2022. Apple discontinued the iPod product line on May 10, 2022. At over 20 years, the iPod brand is the longest-running to be discontinued by Apple. Some versions of the iPod can serve as external USB mass storage device class, data storage devices, like other digital music players. Prior to macOS 10.15, Apple's iTunes software (and other alternative software) could be used to transfer music, photos, videos, iPod game, games, contact information, e-mail settings, Web bookmarks, and calendars to the devices supporting these features from computers using certain versions of Apple macOS and Microsoft Windows operating systems. Befo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITunes
iTunes is a media player, media library, and mobile device management (MDM) utility developed by Apple. It is used to purchase, play, download and organize digital multimedia on personal computers running the macOS and Windows operating systems, and can be used to rip songs from CDs as well as playing content from dynamic, smart playlists. It includes options for sound optimization and wirelessly sharing iTunes libraries. iTunes was announced by Apple CEO Steve Jobs on January 9, 2001. Its original and main focus was music, with a library offering organization and storage of Mac users' music collections. With the 2003 addition of the iTunes Store for purchasing and downloading digital music, and a Windows version of the program, it became an ubiquitous tool for managing music and configuring other features on Apple's line of iPod media players, which extended to the iPhone and iPad upon their introduction. From 2005 on, Apple expanded its core music features with s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Release
The software release life cycle is the process of developing, testing, and distributing a software product (e.g., an operating system). It typically consists of several stages, such as pre-alpha, alpha, beta, and release candidate, before the final version, or "gold", is released to the public. Pre-alpha refers to the early stages of development, when the software is still being designed and built. Alpha testing is the first phase of formal testing, during which the software is tested internally using white-box techniques. Beta testing is the next phase, in which the software is tested by a larger group of users, typically outside of the organization that developed it. The beta phase is focused on reducing impacts on users and may include usability testing. After beta testing, the software may go through one or more release candidate phases, in which it is refined and tested further, before the final version is released. Some software, particularly in the internet and technolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Real-time Computing
Real-time computing (RTC) is the computer science term for Computer hardware, hardware and software systems subject to a "real-time constraint", for example from Event (synchronization primitive), event to Event (computing), system response. Real-time programs must guarantee response within specified time constraints, often referred to as "deadlines".Mordechai Ben-Ari, Ben-Ari, Mordechai; "Principles of Concurrent and Distributed Programming", ch. 16, Prentice Hall, 1990, , p. 164 The term "real-time" is also used in Computer simulation, simulation to mean that the simulation's clock runs at the same speed as a real clock. Real-time responses are often understood to be in the order of milliseconds, and sometimes microseconds. A system not specified as operating in real time cannot usually ''guarantee'' a response within any timeframe, although ''typical'' or ''expected'' response times may be given. Real-time processing ''fails'' if not completed within a specified deadline rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for efficient use of the system and may also include accounting software for cost allocation of Scheduling (computing), processor time, mass storage, peripherals, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computerfrom cellular phones and video game consoles to web servers and supercomputers. , Android (operating system), Android is the most popular operating system with a 46% market share, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Inc
Apple Inc. is an American multinational corporation and technology company headquartered in Cupertino, California, in Silicon Valley. It is best known for its consumer electronics, software, and services. Founded in 1976 as Apple Computer Company by Steve Jobs, Steve Wozniak and Ronald Wayne, the company was incorporated by Jobs and Wozniak as Apple Computer, Inc. the following year. It was renamed Apple Inc. in 2007 as the company had expanded its focus from computers to consumer electronics. Apple is the largest technology company by revenue, with billion in the 2024 fiscal year. The company was founded to produce and market Wozniak's Apple I personal computer. Its second computer, the Apple II, became a best seller as one of the first mass-produced microcomputers. Apple introduced the Lisa in 1983 and the Macintosh in 1984, as some of the first computers to use a graphical user interface and a mouse. By 1985, internal company problems led to Jobs leavin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Closed-source
Proprietary software is software that grants its creator, publisher, or other rightsholder or rightsholder partner a legal monopoly by modern copyright and intellectual property law to exclude the recipient from freely sharing the software or modifying it, and—in some cases, as is the case with some patent-encumbered and EULA-bound software—from making use of the software on their own, thereby restricting their freedoms. Proprietary software is a subset of non-free software, a term defined in contrast to free and open-source software; non-commercial licenses such as CC BY-NC are not deemed proprietary, but are non-free. Proprietary software may either be closed-source software or source-available software. Types Origin Until the late 1960s, computers—especially large and expensive mainframe computers, machines in specially air-conditioned computer rooms—were usually leased to customers rather than sold. Service and all software available were usually supplied ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microkernel
In computer science, a microkernel (often abbreviated as μ-kernel) 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 (computing), thread management, and inter-process communication (IPC). If the hardware provides multiple Protection ring, rings or CPU modes, the microkernel may be the only software executing at the most privileged level, which is generally referred to as kernel mode, supervisor or kernel mode. Traditional operating system functions, such as device drivers, protocol stacks and file systems, are typically removed from the microkernel itself and are instead run in user space. In terms of the source code size, microkernels are often smaller than monolithic kernels. The MINIX 3 microkernel, for example, has only approximately 12,000 lines of code. History Microkernels trace their roots back to Danish computer pioneer Per Brinch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mach (kernel)
Mach () is an operating system 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. The project at Carnegie Mellon ran from 1985 to 1994, ending with Mach 3.0, which is a true microkernel. Mach was developed as a replacement for the kernel in the BSD version of Unix, not requiring a new operating system to be designed around it. Mach and its derivatives exist within several commercial operating systems. These include all using the XNU operating system kernel which incorporates an earlier non-microkernel Mach as a major component. The Mach virtual memory management system was also adopted in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
