General Documents

CTI-TC Cover Page The list of current STIX and TAXII documents in Google Docs
TC Roadmap Current roadmap items, their status, and their proposed release target

Individual Specification Documents

STIX 2.0 Specification

Google Doc Text  
Part 1: STIX Core Concepts Part 1: STIX Core Concepts Defines concepts that apply across all of STIX and defines the overall structure of the STIX language
Part 2: STIX Objects Part 2: STIX Objects Defines the set of domain objects and relationship objects that STIX uses to represent cyber threat information
Part 3: Cyber Observables Core Concepts Part 3: Cyber Observables Core Concepts Defines concepts that apply across all of STIX Cyber Observables
Part 4: Cyber Observable Objects Part 4: Cyber Observable Objects Defines a set of cyber observable objects that can be used in STIX and elsewhere
Part 5: STIX Patterning Part 5: STIX Patterning Defines a patterning language to enable the detection of possibly malicious activity on networks and endpoints

TAXII 2.0 Specification

Google Doc Text  
TAXII 2.0 Specification TAXII 2.0 Specification Defines the TAXII RESTful API and its resources along with the requirements for TAXII Client and Server implementations

OASIS CTI TC Open Repositories

cti-documentation GitHub Pages site for STIX, CybOX, and TAXII
cti-marking-prototype Prototype for processing granular data markings in STIX
cti-pattern-matcher Match STIX content against STIX patterns
cti-pattern-validator Validate patterns used to express CybOX content in STIX Indicators
cti-python-stix2 Python APIs for STIX 2
cti-stix-elevator Convert STIX 1.2 XML to STIX 2.0 JSON
cti-stix-validator Validator for STIX 2.0 JSON normative requirements and best practices
cti-stix-visualization Lightweight visualization for STIX 2.0 objects and relationships
cti-stix2-json-schemas Non-normative STIX and Cyber Observable schemas and examples
cti-taxii-client TAXII 2 Client Library Written in Python
cti-taxii-server TAXII 2 Server Library Written in Python

Other Resources

FreeTAXII YouTube Channel Informational videos about STIX/TAXII - Not affiliated with OASIS