Here is a summary of what's changed since release 21.0. For details and references, see the specific entries in the manual.
There have been relatively few changes to the serial code, apart from some mostly minor bug fixes.
The major change in this version is a reworking of parallelization to include parallel I/O, parallel frequency map analysis (frequency_map), and parallel
momentum aperture determination (momentum_aperture). This work was done by Y. Wang and H. Shang.