12 days of open source

In the spirit of the holidays, we present “12 Days of Open Source”: a 2014 review of stats and fun facts from Facebook’s engineering teams. Check back each work day for a new question and answer from now until the 23rd. Happy Holidays!

Day 12

It’s the last day of “12 Days of Open Source.” Our time of reflection is coming to a close, but we have one more graphic before our 2014 review is over. This one encompasses everything we’ve discussed in the past days.

It’s awesome to see all of this work represented in one place, especially as it reminds us of how much the community comes together to make this work possible. As we’ve said a few times over the course of this review, we truly value the work we get to do with the community. Thanks to you and to the readers of this blog for spending your time with us. Happy holidays — see you in 2015!

Day 11

We worked hard this year to speed up our review process, specifically to get code contributions reviewed and accepted quickly. One measure of this work is the average age of pull requests. That brings us to our next question: How much did the age of pull requests decrease in 2014?

The average age of pull requests decreased by 3x. It’s a big improvement and we’ll continue to work on making the process faster in 2015.

Day 10

For those who couldn’t attend, we turned out in force at OSCON (the Open Source convention). Developers from Facebook covered topics ranging from HHVM to how Instagram.com works. In all, we spoke at seven OSCON sessions this year. Yours truly even suggested that Mozart might be the first open source hacker.

To understand my rationale, check out the first minutes of my OSCON presentation here. You’ll get to listen to some beautiful music in the process.

Day 9

Security may not be the first thing that comes to mind when you think open source, but in 2014 we made two contributions involving security. Which projects were those?

Osquery and Conceal were both released in 2014 and osquery already has a well-known user.

“Osquery is simple, lightweight and was very easy to integrate with the other tools we use. The daemon is easy to configure and the deployment process has been really easy.” – Bryan Eastes / Yelp

Day 8

As promised in the previous days of this series, we’re now giving a shout-out to our top commiters. In 2014, who made the most commits on our open source projects? Drum roll, please…presenting our top five: A special thanks to these folks! And Ben, don’t think we didn’t notice that you’re one shy of 400. There has to be one more item you can contribute, no? (We kid!)

Day 7

We value our relationship with everyone in the open source community, so commits are an important metric we consider as we reflect on our work this year. In 2014 there were more than 28,000 commits on our public projects. How many commits came from external developers?


In 2014, more than 17% of commits on our projects came from external developers, with certain projects like PHP SDK and React earning almost half of their commits from external contributors. Tomorrow we’ll look at those top contributors more deeply.

Day 6

A theme developed as we reviewed the work surrounding our Open Source projects from this year: community engagement growth. We’ve already seen that iOS and JavaScript were popular as starred projects, with Pop receiving more than 9,000 stars. But how much did the number of pull requests grow in 2014?

Many thanks to the developers who worked on these projects! In all, more than 5,500 pull requests were made on these projects this year.

Later this week we’ll look closer at commits and top contributing developers.

Day 5

With 225 Open Source projects in the wild this year, we wondered how many engineers outside of Facebook were contributing to our repos. The answer:

More than 1,000 external developers contributed to our open source projects in 2014, 200 of whom made 5 or more commits. Who were the top contributing developers? Check back next week to find out!

Day 4

One of our favorite parts of open source is working with the community towards solutions that help us all move forward. Check out some of the awesome collaborators and users we had in 2014.

Day 3

Which of our projects that we launched this year have received the most stars on GitHub?


iOS and JavaScript projects proved popular in 2014! Pop received over 9,000 stars in just eight months, with Shimmer, immutable-js, AsyncDisplayKit and (most recently) flow rounding out the top five. Other popular projects launched this year include osquery, flux, tweaks, Bolts, KVOController, WebScaleSQL, proxygen, chisel, jest, and fb-flo.

As always, we’re humbled by your support and contributions, and we hope you continue to find these projects valuable!

Day 2

How many new Open Source projects did Facebook launch in 2014?


We launched 107 new projects, which between them earned 65,000 stars and more than 6,000 forks. Tomorrow we’ll reveal the projects that received the most stars. Any guesses as to who will be at the top?

Day 1

Which one of Facebook’s flagship projects HHVM or React reached 10,000 stars on GitHub first?

Answer: React, but just by a touch. The React team activated their social networks faster and overtook HHVM in the end, but both ended up hitting 10,000 stars on the same day!


Next in the 10,000 club will be Pop. Anyone care to guess who the the 10,000th follower will be?

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