Skip navigation

Supporting sustainable communities

GitHub continues to grow as home for developers

GitHub welcomed 1.4M new contributors to open source this year, and our community continued to build software that powers the world.

At GitHub, we care a lot about supporting our community and its priorities. Check out the survey findings and how it shapes GitHub’s policies

Read more about our policy

Number of first-time contributors for open source projects, by year

Total repositories on October 1

GitHub’s developer community spans dozens of languages, frameworks, and areas of interest. Open source is sustained through the work of contributors, maintainers, and the work of other open source projects. We’re continually giving back to each other.

190M+Repositories in October 1, 2020254M+Repositories in October 1, 2021

Our community builds and supports other communities

Our community builds and supports other communities. We came together to support Discord.


Mentorship is a community asset in both open source and companies

What the data shows: When new contributors get friendly and timely reviews, and there is a commitment to mentorship, teams see a positive effect on productivity -- 46% improvement in open source, and 16% in companies. Beyond productivity though, mentorship can be a multiplier for healthy and sustainable communities. Explicitly providing mentorship almost triples the chances of an open source team having a healthy culture, as well as contributors feeling they belong in the community and identifying with the work they do. For teams at work, mentorship almost doubles the likelihood of a strong culture.

Using the data: Use these charts to identify one thing you can work on to improve your work! Pick something on the right (at the end of an arrow), then work backwards to see what has a significant effect. For more details about each construct, head to the companion repository for the survey items we used.

How communities sustain productivity

Each box in the model is a construct (either a practice of development work, documentation, or healthy communities; or outcome of doing these things well). Each line is a predictive relationship between constructs. When you see a line, you can generally read it as “predicts” or “affects”. Colored lines are positive relationships, and gray lines are negative. For this particular section the model did not show any negative relationships (hence, no gray lines).

Open source
Graph about developer productivity in Work

Trust and respect contribute to a strong culture

What the data shows: We found a very strong positive effect that was (perhaps surprisingly) higher in teams at work than teams in open source. Teams with high trust are more likely to have a healthy collaborative culture -- 2x more likely in companies, and 3x more likely in open source. Mentorship contributes to a developer’s sense of identity and belonging in their community, but a very strong culture (as measured by Westrum) can reduce the need for mentorship.

Using the data: Are you setting your organization or community up for sustainable productivity? Investing in mentorship is an investment on improving culture, which has long-lasting benefits for productivity, satisfaction, and retention.

Teams with high trust are more likely to have a healthy collaborative culture:

2XMore likely in companies3XMore likely in open source

Safe and welcoming communities attract newcomers and encourage contributions

What the data shows: The largest repositories use codes of conduct as a welcome sign. In addition, contribution guidelines, Good First Issues, and respectful language in Discussions signal a community is safe and trusted. Communities with these signals attract more contributors, create a stronger sense of belonging and fulfillment, and help developers make progress on their work.

Using the data: Look at your own projects and repositories: Are you signaling they are safe and welcoming with things like Good First Issues, codes of conduct, or something similar?

Number and proportion of repositories with and without code of conduct, by repository type

> 5 Contributors
> 1000 Contributors
With code of conduct
Without code of conduct

Open source repositories

Open source at work repositories

Work repositories

We found that the positive effects of trust and safety work in both open source and company settings, and for both small and large repositories.

While repositories and teams in companies may not be using the exact same practices as welcoming open source communities do (such as formal codes of conduct), we should think about how we can signal and create safe teams at work.


Fun and learning fuel newcomers’ initial attraction to open source communities

People interested in open source can get involved through hobbies and special interest groups - not just deep technical communities.

What the data shows: The top 20 repositories by contributors are communities with topics such as gaming, manga, science, and education.

Top 20 large repositories by percent new contributors with account age <2 years

Top 20 large repositories by category and repository contributors

Click on the circles to discover the number of repository contributors and % of contributors with account age <2 years. The descriptors came from the project READMEs.


Building and supporting stronger communities

These findings show us why developers care so much about development and how important it is to support our work:

It provides a sense of community and gives us a place to make and create something bigger than ourselves.