ACT Marks Milestone of 1,000 Contributions!

Published: 28 May 2026

Editor’s note: The Atmospheric data Community Toolkit (ACT) team provided the following post.

A graph shows pbl_gradient in meters from 0 to 7,000 on the y-axis and time from 0 to past 21:00 on the x-axis. There is also a legend for attenuated volume backscatter coefficient [log(1/(m*sr))] from less than -4 to -8. A black line zigzags across the plot in the 0- to 1,000-meter range for the full day. Text underneath the graphic says "Read ceilometer data for an example," "apply corrections to the data set," and "estimate PBL height via a gradient method," with code following each of those prompts. — An example of a community-requested feature that was recently submitted to the Atmospheric data Community Toolkit (ACT) estimates the planetary boundary layer height via a gradient method (i.e., identified through the sharpest negative gradient) from a ceilometer. Additional pull requests will be included within the near future to address more planetary boundary layer environmental conditions. Image is from Joe O’Brien, Argonne National Laboratory.

The ARM-supported ACT Python library has reached a major milestone with its 1,000th merged pull request (code contributed back to ACT), highlighting years of sustained development in support of open-source software. Fittingly, the milestone pull request was a team effort, with four ACT developers contributing to it as a way to celebrate the collaborative spirit that has defined ACT since its repository opened in December 2018.

While the 1,000th pull request—a mix of updates and fixes—marks a software development achievement, it also represents something broader: the growth of research software as critical scientific infrastructure. Every pull request represents an idea, reviewed, improved, and incorporated into a shared resource for the scientific community.

ACT has developed into a trusted toolkit for atmospheric data exploration, visualization, quality control, and reproducible scientific workflows. ACT has had 16 contributors from the beginning who have steadily expanded ACT’s capabilities while ensuring the software is maintained to a high standard.

The pull request milestone is accompanied by growing recognition of ACT within the open-source community. The project has earned 182 GitHub stars, which are given when someone wants to bookmark a repository or show appreciation on the GitHub developer platform. Over 60 r epositories are dependent on ACT, and the project has recorded 40 repository forks (copies of ACT code that users have taken to work with in their own accounts), showing that ACT is supporting ARM and the broader scientific community.

This milestone is also seen as a launching point for ACT’s next phase, documented in the third ACT Roadmap. In this new roadmap, developers incorporated valuable feedback from the user community to prioritize features and identify areas where community contributions are encouraged. The highest-priority items include developing new guidelines that cover the use of artificial intelligence by users and maintainers, expanding support for ARM’s aerial platforms, and creating ARM summer school tutorials.

As open-source tools play an increasing role in scientific discovery, ACT is positioned to continue growing into the future as a platform for collaboration, innovation, and community-driven research.

That future is open to new contributors. Whether through code development, documentation, tutorials, feature requests, or sharing new scientific workflows, ACT welcomes participation from researchers, students, and developers interested in helping shape the toolkit’s next chapter. As the community looks beyond 1,000 pull requests, the project’s developers hope this milestone serves not only as a moment of reflection but also as an invitation for others to help build what comes next.

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ARM is a DOE Office of Science user facility operated by nine DOE national laboratories.