OpenDarwin Shuts Down as Apple Opens Up Mac OS Forge

Published: August 10, 2006

by Timothy Prickett Morgan

If I could make a set of broad generalizations, I would say that companies that have a heritage in closed source operating systems seem to have the hardest time fully embracing the concept of truly open source, community developed software; they also seem to be very much eager to enjoy the benefits of the open source development community at large and to figure out ways of commercializing the software stacks they develop. So it is with Apple Computer and its Mac OS operating system.

As many of us know, Mac OS X, the operating system that runs on Power and now X64 Mac PC and Xserve servers, is based on a variant of the Mach 3.0 Unix kernel from Carnegie Mellon called XNU. To make Mac OS X, Apple weaves a layer of FreeBSD services--FreeBSD being one of the three major distributions of BSD Unix--and then adds its own graphical user interface and other goodies that make a Mac a Mac. Mac OS X has its heritage back in the OpenStep platform that Steve Jobs and his team at the former NeXT Computer, which was absorbed into Apple when Jobs, one of Apple's two founders, was brought back to save the company from oblivion in 1996. This software, which was very sophisticated, was the foundation for "Rhapsody," the Mac OS X operating system, which made its debut in 2001. Apple decided before then to fork the Rhapsody code, take out some of the goodies, and open source that software under a project called "Darwin."

The interesting thing about Darwin, aside from being an open source implementation of Mac OS X, is that the project has been releasing code for PowerPC and X86/X64 processors for the past five years. Even though Apple did not officially start supporting Intel iron until this year, when Apple itself made the jump from Power to X64 Core processors for its own machines, if you really wanted to make Darwin run on an X86 or X64 box, you could do it.

After Apple took Darwin open source (keeping its own user interface and other features for its own machines), the OpenDarwin project was created to try to create a development community around Darwin. There are a number of other Darwin projects, including GNU-Darwin, but OpenDarwin was the focal point for what, as it turns out, is a community that never really got going. Which is why the members of the OpenDarwin project announced on July 25 that they had had enough and were shutting down.

You can read the announcement by the OpenDarwin project as to why it is closing down on its home page--at least as long as it is available--but this passage pretty much sums up the situation:

"Over the past few years, OpenDarwin has become a mere hosting facility for Mac OS X related projects. The original notions of developing the Mac OS X and Darwin sources have not panned out. Availability of sources, interaction with Apple representatives, difficulty building and tracking sources, and a lack of interest from the community have all contributed to this. Administering a system to host other people's projects is not what the remaining OpenDarwin contributors had signed up for and have been doing this thankless task far longer than they expected. It is time for OpenDarwin to go dark."

The basic problem is that Apple likes to control its technologies and it likes to keep future developments secret until they are launched, but at the same time it needs to keep its open source credentials in the 21st century. So Apple this week launched the Mac OS Forge to host Darwin and related Mac OS X projects. While Mac OS Forge will keep these projects alive and Darwin going, in as much as it was going, it does not solve some fundamental problems with Apple's approach to open source. Mac OS Forge, like OpenDarwin before it, lets people see what Apple's operating system developers did in the current release of Mac OS--excepting some code it keeps secret--but neither Mac OS Forge nor OpenDarwin have the means to allow outsiders to see what it Apple is doing, right now, in the subsequent release or to allow them to contribute to the future cause. In the strictest interpretation, this is not an open source project, which assumes collaboration and unstable as well as stable code trees, as it is an open source repository of stable code, which will allow very smart nerds to build a system very much like Max OS X if they have the time and skills to do it. This is not how Linux or the various BSD projects work. But, you always expect Apple to cut its own path through the jungle.

In any event, the Mac OS Forge site is now hosting the source code for Mac OS X 10.4.7, the latest "Tiger" release, for both X64 and PowerPC processors. (You can read Apple's announcement of the creation of the Mac OS Forge, which was posted by Apple's open source product manager, Ernest Prabhakar, by clicking here.) Mac OS Forge has already taken in the orphaned Webkit Web browser project, and will probably pick up all of the other projects, too, from the OpenDarwin site. Apple also announced that the site would be iCal Server calendar server, due in the "Leopard" Mac OS X server due in early 2007, is being released under the Apache License. The code behind the Bonjour service discovery and Launchd process management software that was previously available is now available under the Apache License, too, at the Mac OS Forge site.