ACME is an open-source implementation of a Common Service Entity (CSE) based on oneM2M standards. It is widely used for educational, concept testing, and research purposes. A new release is now available (see link below) with security and configuration enhancements. It also contains experimental features that build on discussions in oneM2M's Technical Plenary working groups. They include implementations of a new "No Response" feature, to reduce data traffic and improve energy use, and revised FlexContainer procedures. Updates to the new release also address small improvements, corrections, and internal refactorings.
The ACME oneM2M CSE repository is accessible via this link: https://github.com/ankraft/ACME-oneM2M-CSE.