For months Black Duck Software CEO Doug Levin has been writing a blog. It is interesting and offers useful insights into the open source community, software development and other things. After a series of inquiries, I slowly came to the conclusion that this was a good way to share my point of view as well. So I am writing this blog.
As you may know, Black Duck Software maintains a database of all the open source code that we know of, and this database gets updated continuously day in and day out.
This morning I took a look at the amount of open source code that we receive every day. I decided to only look at new unique source files found in actual project releases - ruling out non source code - e.g. documentation and binaries, interim code - which is not officially released, and duplicates of existing files that developers reuse from the same or other open source projects. Even so, approximately 4.7 million lines of code is added everyday - which translates into 1.7 billion lines of code each year. Although we are probably missing some parts of open source out there - which would make this an underestimate, we can take a leap faith and use this as a proxy for the amount of open source code created in the world, and then we can get some idea of the value created by the open source community.
Now let's make a bunch of assumptions and try to see the value of the effort in creating such an amount of code. Assuming an average open source project is 35,000 lines of code and the average cost of a software developer is $30/hour (~$60,000/year), a simple COCOMO II calculator tells us that the average open source project costs $630,000 to develop. This cost translates into $18 per line of code. Extrapolating that to 1.7 billion lines of code gives us an estimated value of $30.6 billion/year. Changing perspective for a second, if the open source community was a country with a GDP of $30.6 billion, it would rank 77 right between Bulgaria and Lithuania according to the International Monetary Fund's list of GDP by country, thereby putting the open source community ahead of most countries in the world.
You can argue about whether this number is high or low, and you can argue whether the basic COCOMO calculation on a 35,000 line project can be extrapolated. However, the $30 billion/year number seems consistent with previous estimates such as David A. Wheeler's More Than a Gigabuck: Estimating GNU/Linux's Size estimating the cost to develop all elements of the Red Hat Linux 7.1 distribution as $1.08 billion, and the study: Economic impact of open source software on innovation and the competitiveness of the Information and Communication Technologies (ICT) sector in the EU estimating the cost to develop the elements of the Debian 3.1 distribution (until 2005) at €11.9 billion -- increasing to a cumulative €100 billion (~$146 billion) by 2010.
According to these rough calculations, the direct economic impact (ignoring any indirect economic impact) of the open source community appears to be larger than the economic impact of most individual countries in the world. Even if the numbers could be somewhat off and not a perfect measurement of impact, it does show that the development cost of open source is in that same order of magnitude as many countries' GDP. Such an economic force should not be underestimated, and this is yet another indication that open source has become a significant part the technology world.