Object Oriented Data Technology (OODT) is a software framework to support metadata (profile) and data (product) search and retrieval. It's written in Java. It has client APIs in C, Java, and Interactive Data Language, as well as supports HTTP access, enabling easy integration into web-based applications. Combining a simple installation process (and a self-installer on Windows platforms) with remote management capabilities makes it easy to deploy far and wide.

OODT is middleware for metadata: Transparent access to distributed resources Data discovery and query optimization Distributed processing and virtual archives	OODT is a software architecture: Models for information representation Solutions to knowledge capture problems Unification of technology, data, and metadata
How does it work? An example of what it does Our classic paper (and a good conceptual intro, too)	Who's using it? National Institutes of Health NASA Planetary Data System NASA SeaWinds Earth Science Mission NASA QuikSCAT Earth Science Mission Dozens of institutions Space, planetary, biomedical, and other domains