Shared Near Infrared Spectroscopy Format (SNIRF) is designed by the community in an effort to facilitate sharing and analysis of NIRS data.
The specification can be found on GitHub here. Version 1.0 was officially released in September of 2021 after almost 2 years in draft version getting feedback from those adopting it. You can find the specification, software, and sample files through GitHub. An community of developers using snirf are actively contributing to discussion about the specification on github. Please join in on the discussion.