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The 2018 ROS Metrics Report


We’ve posted the annual ROS Metrics report for 2018. You can download it from here and it’s been added to the Metrics wiki page where you can find links to all the previous versions as well.

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

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. This year we haven’t updated any fields.

In this report the biggest thing that stood out to me was the growth of ROS Discourse. The delta on the number of users might be a little off due to estimations to correct the spam attack last year. But reviewing all the numbers there’s been a lot more activity overall on Discourse.

One outlier that I believe is not super representative is that the number of wiki pages dropped. Part of this is because when I was collecting the number I realized that we hadn’t run our periodic “trash” page cleanup. This is a technical term from the Moin Moin Tuning Guide and maintenance routines for pages that have metadata that’s created but no content. One of the things that Moin Moin does is that it creates pages if you browse to them by accident. So every 404 creates a “trash” page. When collecting the stats I noticed that we had way too many pages and ran the cleanup script which removed 14750 pages, otherwise it would look like we almost doubled the number of pages. This has not been run immediately preceding the stats collection in the past so it adds noise to the measurements based on how long from the last cleanup operation. In the future I’ll plan to run the cleanup before collecting stats.

2018 Metrics report

As per last year, here’s everything plotted.

It seems like the visitor locations data is off somehow, as the overall metrics don’t show a drop, but by country, the stats are significantly lower than last year. Update: Fixed based on Tully’s data below.

02%20-%20ROS%20Answers%20Website%20Metrics 03%20-%20Communication%20Platforms 04%20-%20Wiki%20Stats 05%20-%20ROS%20Answers%20Stats 06%20-%20Total%20Downloads 07%20-%20Unique%20IPs 08%20-%20Papers%20Citing


Thanks for the informative historical graphs @DLu

The change in the country information appears to be due to Google switching to have the default metric be “Users” now instead of “Sessions” I didn’t notice the change in metric. I think the new user metric is more valuable but it doesn’t capture the trend lines as well. It’s also interesting to see the different ratios of sessions vs users.

Here’s both side by side:


I’ve updated the plot. Do you think it’d make sense to keep the same metric going forward, or do you want to switch to Users for the future Metrics reports?


I’d like to switch to the user metric as it’s a little more informative than sessions. For the ongoing consistency of the charting it could be switched to just be a ratio and then the older session data and the newer user data is comparible. The growth curve actually hides some of the earlier information by compressing it, especially if we keep growing.