The Data Transfer Project makes it easy for platforms to build interoperable user data portability features. We are establishing a common framework, including data models and protocols, to enable direct transfer of data both into and out of participating online service providers.
Manifold is a Java compiler plugin, its features include Metaprogramming, Properties, Extension Methods, Operator Overloading, Templates, a Preprocessor, and more.
Apache Polaris, the interoperable, open source catalog for Apache Iceberg
Apache XTable (incubating) is a cross-table converter for lakehouse table formats that facilitates interoperability across data processing systems and query engines.