Anti-Rivalness of Free Software
Steven Weber, the author of the landmark book, The Success of Open Source, argues that it is not enough to characterize free software as a non-rival resource, it is more than than, anti-rival.
Excerpt from Page 153f:
"I believe the solution to this problem lies in pushing the concept of non-rivalness one step further. Software in many circumstances is more than simply non-rival. Operating systems like Linux in particular, and almost software in general, actually are subject to positive network externalities. Call it a network good, or an anti-rival good (an awkward, but nicely descriptive term). In simpler language, it means that the value of a piece of software to any user increases as more people use the software on their machines and in their particular settings. Compatibility in the standard sense of a network good is one reason why this is so. Just as it is more valuable for me to have a fax machine if lots of other people also have fax machines, as more computers in the world run a particular operating system or application it becomes easier to communicate and share files across those computers. Each becomes slightly more valuable to existing users as each new users enters the picture.
Open source software makes an additional and very important use of anti-rivalness, in maintenance and debugging. Remember the argument that there exists an infinite number of paths through the lines of code in even a moderately complex piece of software. The more users (and the more different kind of users) actively engage in using a piece of software, the more likely that any particular bug will surface in someone's experience. And once a bug is identified, it becomes possible to fix it, improving the software at a faster rate. Thus is hugely important to the economics of software users, because customization, debugging and maintenance usually accounts for at least half (and sometimes considerably more) of the total cost of ownership of enterprise software.
The point is that open source software is not simply a non-rival good in the sense that it can tolerate free riding without reducing the stock of the good for the contributors. It is actually anti-rival in the sense that *the system as a whole positively benefits from free riders*. Some (small) percentage of free riders will provide something of value to the joint product - even if it is just reporting a bug out of frustration, requiring a new feature, or complaining about a function that could be better implemented. In fact one wonders if it makes sense to use the term "free rider" here. Regardless - the more "free riders" in this setting, the better."