This guest post was submitted by Ole Tange, maintainer of GNU Parallel.

I am the maintainer of a piece of free software called GNU Parallel. Free software guarantees you access to the source code, but I have been wondering how many actually read the source code.

To test this I put in a comment telling people to email me when they read this. The comment was put in a section of the code that no one would look to fix or improve the software -- so, the source code equivalent to a dusty corner. To make sure the comment would not show up if some one just grepped through the source code I rot13'ed the source code.

Two-and-a-half months later I received an email from someone who not only managed to find the comment, but also managed to guess the code had to be rot13'ed.

The first cookie was released on January 24, 2011 and was won by AEvar Arnfjord Bjarmason on April 10, 2011.

I inserted a new cookie on August 18, 2013, that was a bit harder as you would have to use rot14. On July 19, 2015 Mark Maimone won that cookie.

This brings me to the conclusion that there are people who are not affiliated with the project who will read the source code -- though it may not happen very often.