• Gaia-X (participation, blog, academy) • GXFS-DE (XFSC) implementation • EDC Connector implementation • FIWARE implementation (XACML) • Rego and Open Policy Agent • Mature but no Gaia-X (or JsonLD, VC/VP) support • Trust Server API (GXFS-DE) is based on OPA • ODRL: Open Digital Rights Language (later chosen by Gaia-X as standard) • Specification without a reference implementation • Supports customization through profiles like Gaia-X’s OVC • Multiple implementations • Gaia-X “Policy Reasoning Engine” • Uses Graph Database – not fast enough for our needs • EDC Connector implementation • Complex to use: See Access Policies Tutorial – therefore hard to get right. • FIWARE: Keyrock, Wilma PEP Proxy, and Authzforce • XACML (eXtensible Access Control Markup Language) • IMHO: Unpleasant to create and maintain as text. See Example from Docs. It makes it hard to get policies right.