Metacat

Metacat is a repository for data and metadata (data about data) that helps 

scientists find, understand and effectively use data sets they manage or that 

have been created by others. Thousands of data sets are currently documented in 

a standardized way and stored in Metacat systems, providing the scientific 

community with a broad range of science data that--because the data are well and 

consistently described--can be easily searched, compared, merged, or used 

in other ways.