Microsoft is granting Azure credits to open source projects to help with their testing, builds, and other development work.

Here's more about some of the projects already participating in the program.

FreeBSD
FreeBSD is a Unix-like operating system for servers, desktops, and embedded platforms. Azure credits have helped developers to work on custom kernels. They are now releasing more timely updates for security advisories for third-party software and spinning up larger VM classes for package building and smaller VM classes for testing, both of which are hugely helpful to their developers.
AlmaLinux
AlmaLinux OS is a 1:1 binary compatible clone of RHEL®, guided and built by the community. They were the first downstream RHEL clone to be released after the announcement by RedHat that support for CentOS Linux was ending, and their goal is to provide an option for folks who have historically used CentOS Linux, and for whom CentOS Stream is not an option. The AlmaLinux OS Foundation is a 501(c)(6) non-profit created for the benefit of the AlmaLinux OS community.
Haskell
Haskell is a purely functional programming language. Azure credits are helping their continuous integration system, releases, their GitLab instances, and other builds.
Snakemake
The Snakemake workflow management system is a tool for creating reproducible and scalable data analyses. Workflows are described via a human-readable, Python-based language, and Snakemake enables these to be seamlessly scaled to server, cluster, grid, and cloud environments.