Darwin Streaming Server: Open, Functional and Free
Microsoft and RealNetworks make wonderful streaming server products that have been proven in the marketplace and production environments. They certainly have every reason and right to charge money for their software. By the same token, they have every right to hold onto their source code and their proprietary technologies as tightly as they wish, licensing them out only when they choose to do so. In turn, Apple has the right to charge no money for its streaming server, to give the source code away for free, and to invite the world to participate in its evolution. The Darwin Streaming Server is proof that Apple has chosen to exercise all three of those rights.
Version 3 of the Darwin Streaming Server was released at the same time as QuickTime 5, back in April of this year. While it supports older QuickTime clients, it offers some advanced capabilities that only work with QuickTime 5. It runs on many platforms, and it makes pretty short work of stream serving. My testing revealed that although the product is a little rough around the edges, such as with support scripts, the core streaming server proved to be a reliable workhorse for basic streaming tasks. Read on to find out what it takes to set it up and whether or not it is right for your needs.
The Darwin Streaming Server is the open source, free version of the QuickTime Streaming Server, distributed as part of the Mac OS X Server. It currently runs on Linux, Solaris, FreeBSD and WindowsNT/2000. And, since the source is also available, this list of platform choices is sure to grow. I did my testing with Darwin Streaming Server 3.0.1 and a few different versions of QuickTime.
The Darwin Streaming Server (DSS) is comprised of the actual Streaming Server as well as a number of supporting applications, such as the Streaming Admin Server for Web-based administration and the Playlist Broadcaster for radio- or TV station-like continuous broadcast of content. It is also possible to control client access to any streaming content, at an individual or group level.
The DSS serves hinted QuickTime files and live broadcasts via industry standard Internet protocols RTP/RTSP. It can unicast, sending one stream per client, or multicast, sending only a single stream to all clients. The DSS can host up to 3,000 simultaneous streams, according to the documentation; however, my setup did not allow robust enough load balance testing for me to confirm or deny this claim. DSS also touts a relay capability, which allows a Streaming Server to be set up as a relay to additional Streaming Servers to support an almost unlimited number of simultaneous users.
QuickTime 5 and DSS 3, when used together for streaming, have 'Skip Protection,' a vaguely defined feature designed to reduce interruptions to an end user's streaming experience.
With the help of the Streaming Admin Server, the Streaming Server can also be configured and monitored remotely via a Web browser, and in English, Japanese, French or German.