Unidata is partnering with OPeNDAP, Inc. and the University of Washington eScience Institute on the OPeNDAP-Unidata Linked Servers (OPULS) project to better align, link and eventually integrate software that OPeNDAP and Unidata independently offer as open-source packages. The union of the capabilities provided by these extensible software offerings has become increasingly important as basic infrastructure for scientific data exchange.

The purpose of the OPULS project is to adapt the OPeNDAP and Unidata server systems (Hyrax and TDS, respectively) for greater conformance, linkage, and eventual integration. Over the course of the project, we also hope to demonstrate how each group can capitalize on advances achieved by the other.

In the initial stages of the project, we will focus on data-model and protocol specifications, along with server conformance testing. Although these activities only set the stage for a common server framework, the resulting tests and specifications will immediately enhance the interoperability of the two server systems. We also anticipate that other OPeNDAP-related systems (such as PyDAP) will be adapted by their authors to pass conformance tests put forward jointly by OPeNDAP and Unidata.

In parallel, the project will experimentally extend Hyrax and/or TDS to offer server-side subsetting of non-rectangular meshes/UGRIDS (using software developed by the University of Washington eScience Institute) and to offer asynchronous client-server interaction (as would, e.g., facilitate serving "near-line" data, perhaps stored on robot-mounted tapes). Later, these extensions will be employed to test a new form of Hyrax-TDS linkage, permitting TDS users to utilize Hyrax advances and vice versa.

In later stages of the project, OPeNDAP and Unidata will jointly explore use of an OSGi-style framework to resolve architectural and use-case differences between Hyrax and TDS.