Darwin (operating system)

From ArticleWorld

Darwin is a free Unix-like operating system, and the core of Apple Mac OS X. It was released by Apple in 2000, and continuously maintained by the OpenDarwin community. Its logo is Hexley the platypus.

Structure

Darwin is based on the XNU microkernel, a Mach-derived, Unix-like kernel. It includes message passing capabilities and memory protection. It has real-time support, as well as extensive kernel debugging support.

XNU also has a special binary format, the Mach-O binary format, allowing the OS to contain binaries for different architectures in the same file. Darwin runs on x86 and PPC processors, with full SMP support.

An important part of Darwin consists of BSD code. It is the part that provides BSD system calls, the process model, most networking and VFS code, as well as a strong cryptographic framework and the System V IPC support.

The I/O Kit is a device driver framework, which uses a subset of C++. The I/O Kit is an important feature, because it provides an object-oriented model for device drivers, allowing them to be written more quickly and easier. The I/O Kit includes multi-threading, and SMP support, as well as hot pluggable devices and dynamic device configuration.

Darwin is released under the APSL 2.0 license since 2003, a FSF-approved Free Software license. Previous releases were not approved by the FSF as valid free software because of their license (APSL version 1).

Distributions

The flagship Darwin distribution is OpenDarwin, but there are two other distributions: Speedcake, which tries to create a Gentoo-like package management system, and TevaX, which tries to create a Mac OS X clone.

Popularity

Darwin is, at the moment, a quite popular operating system, especially on the PowerPC. It is also the base of many projects and hosts a significant number of public websites.