We started collecting metrics in 2011. Reviewing the history you can see the growth and evolution of the community.
Measuring open source communities is very hard. The nature of being open and redistributable means that we definitely do not know everyone who is using it and that’s part of being open. These metrics can provide insight into trends within the community but should not be considered exhaustive or even close to complete but as a consistent snapshot. We have public instructions for setting up mirrors and these measurements do not count the any statistics for mirrors either private or public. Public mirrors are listed at http://wiki.ros.org/Mirrors
Every year we seek to provide the same metrics so that trends can be observed. However we also look to update the metrics to include new statistics or cover new aspects that we think may be interesting trends in the future. For example we started sampling the architecture usage last year as there has been growing interest in armhf and arm64, while i386 is now dropping off in usage having previously been the most popular architecture.
In assembling this report there were several statistics that stood out to me. The biggest one is that we’ve more than doubled the number of unique visitors to packages.ros.org in the last year. This is one of the best proxies for the size of the community. Other statistics such as download counts and bandwidth usage can be highly dependent on exactly which packages get released in any given time period.
Two statistics are notable outliers. One is the number of users on discourse.ros.org there’s currently a spam attack with new unverified users being created semi-automatically. They are not getting past the verification stage and cannot post. However, the site includes them in their user count and I don’t have a good way to exclude the unverified users. They will automatically be cleared after 7 days unverified. And the other statistic that is a little bit skewed is the number of robots. This year we’ve switched from wiki.ros.org/Robots to http://robots.ros.org In the process of switching there was a bit of a review process. However, clearly with the new website submissions are down too. We’ll need to look at making that more accessible as I’m quite confident that this metric is now under-reporting.