After 6 years and multiple versions and Ballots the final stable STIX2.1 has been released. It will now be eligible for consideration as a standard under the auspices of the International Telecommunications Union (ITU) among other global bodies.
Structured Threat Information Expression (STIX) is a language and serialization format used to exchange cyber threat intelligence. STIX enables organizations and tools to share threat intelligence with one another in a way that improves many different capabilities, such as collaborative threat analysis, automated threat exchange, automated detection and response, and more.
STIX v2.1 adds new objects and concepts and incorporates improvements based on experience implementing Version 2.0. The objects and features added for inclusion represent an iterative approach to fulfilling basic consumer and producer requirements for CTI sharing. Objects and properties not included in this version of STIX, but deemed necessary by the community, will be included in future releases.
On June 11, 2021 Chet Ensign of OASIS announced:
OASIS is pleased to announce that the call for consent has closed  and, effective 10 June 2021, STIX Version 2.1 and TAXII Version 2.1 are approved OASIS Standards. Project Administration will now undertake the final tasks of preparing and loading the standard.
The ballot was held under the OASIS call for consent procedure . In the ballot, the Candidate OASIS Standard received 13 affirmative consents and no objections.
Our congratulations to the members of the CTI TC and to the community of implementers, developers and users who have brought the work successfully to this milestone
Until such time as the new STIX CS03 Version is released, please use the following for the final: