Apple公司最近放出了Darwin9操作系统的源码，这个系统是Apple公司目前的OS X10.5，代号为猎豹的苹果机操作系统的蓝本。Darwin是一款基于Unix的操作系统，其中包含了许多apple公司的技术理念，比如Mach 3.0微内核、基于FreeBSD 5的Unix服务机制，以及高性能的TCP/IP网络，还有，就是支持多种集成文件系统。Darwin系统本身的模块化程度非常高，你可以动态自由地扩展 设备驱动、网络扩展和文件系统等等。
原文如下：
Apple has released the source code to Darwin 9, the underlying open source operating system ofMac OS X 10.5 Leopard. "Darwin is the open source UNIX-based foundation of Mac OS X. Darwin integrates a number of technologies, including the Mach 3.0 microkernel, operating system services based on FreeBSD 5 UNIX, high-performance TCP/IP networking, and support for multiple integrated file systems. Because the design of Darwin is highly modular, you can dynamically add device drivers, networking extensions, and new file systems."
源码下载地址：
http://www.opensource.apple.com/darwinsource/10.5/