A new beta release of MPICH, 4.1b1, is now available for download. This is the first feature-complete release in the 4.1 series. Major features in this release include:

• Standalone libpmi
• Independent use of MPICH testsuite
• Experimental MPIX stream prototypes to support explicit threading context and asynchronous enqueue to GPU streams. Both CUDA and HIP are supported.
• Significant refactor in PMI and Hydra

The full set of changes since 4.0.3 can be found here: https://github.com/pmodels/mpich/compare/v4.0.3…v4.1b1