The document outlines updates to the MITRE ATT&CK® software, highlighting significant changes such as the retirement of the TAXII 2.0 server and the introduction of the TAXII 2.1 server, which will serve STIX 2.1 data. It also details enhancements to ATT&CK Navigator, including a new review checkbox and a redesigned user interface, as well as updates to the website and ATT&CK data model. Future developments include process improvements for the workbench and a transition to a modern framework for the website.