OpenIsis provides a library and tools to access CDS/ISIS databases, which are mostly used for bibliographic data (ISO2709, Z39.50) but also well suited for other catalogues due to the very flexible indexing mechanism. Based on a C library, there are also bindings for Perl and Java (Tcl to come).
The Virtual Data Center (VDC) is a digital library system "in a box" for numeric data. It provides a complete system for the management, dissemination, exchange, and citation of virtual collections of quantitative data. It provides everything necessary to maintain and disseminate an individual collection of research studies: including facilities for the storage, archiving, cataloging, translation, and dissemination of each collection. On-line analysis is provided, powered by the R Statistical environment.