This version represents an incremental update that incorporates a number of changes for additional consistency and expressiveness, particularly with regards to the representation of MAEC Actions and Objects. This stems primarily from the integration of the Version 1.0 (Draft) of the Cyber Observables Expression (CybOX(tm)) Schema and its components, where appropriate. Also included with the release for the first time are a set of Schematron rules for performing additional validation of MAEC documents. Due to the extensive changes in CybOX Version 1.0 and additional changes and revisions, MAEC 2.1 is not backwards compatible with MAEC 2.0.
As always, we encourage your feedback and comments/questions. In the near future, look for some additional discussions regarding MAEC bundle management, behaviors, and related topics. We're also standing up a MAEC Github repository for housing MAEC-related scripts and utilities, which we'll be announcing soon.
MAEC Working Group
The MITRE Corporation