H. E. Payne, R. J. Hanisch
STScI
A. Warnock
A/WWW Enterprises
J. Fullton
CNIDR
The Astronomical Software Directory Service (ASDS) is a WWW-based utility for locating astronomical software and tools. The ASDS concept was described at ADASS III (Hanisch et al., ASP Conf. Ser. 61, p. 41) and the initial version of the facility was demonstrated at ADASS V (Payne et al., ASP Conf. Ser. 101, in press). A key design feature of ASDS is that it indexes documents distributed around the Internet and maintained by the software providers, rather than working from a centralized documentation database. In addition, we also provide a uniform set of high-level package descriptions. ASDS (http://asds.stsci.edu/asds/) utilizes the Isearch text search and retrieval engine developed by CNIDR (http://www.cnidr.org), and is a beta test site for the commercial version of this package. In contrast to earlier versions of ASDS, searching no longer requires immediate access to the source documents. This substantially improves search response time by eliminating the network retrieval of documents, and removes the sensitivity of the search process to changes in the original documents. The tradeoff for the elimination of network traffic during searching is the imposition of a limitation on the length of query phrases. Searching for phrases--not individual words--longer than a threshold length still requires retrieval of the documents over the network. However, the threshold length is configurable at compile time. The text indexer has been modified for the ASDS to retrieve remote documents specified by URL.