b) ZNavigator: An open, general purpose, highly functional Z39.50 Windows client application. ZNavigator may be used as a stand-alone application, or as a Cactus-controlled one. In the latter case, details of Z39.50 targets available to the user are received from the Cactus Server, and detailed statistics of connections usage are maintained.
Z39.50 is becoming quickly the most widely used protocol for accessing bibliographic, library and document databases. Unfortunately, most of the commercially available Z39.50 clients are strongly tied to the server software running on the opposite side of the connection. This means that if you want to have access to different servers on different locations you will probably need more than one client to meet the specific needs of each server. ZNavigator overcomes this problem, having been designed as a highly general tool, supporting most of the requirements and facilities defined by the Version 3 of the Z39.50 standard. As the Z39.50 standard matures, ZNavigator will include more and more facilities facilities to allow for greater interoperability.
ZNavigator is a multi-threaded application, allowing you to have more than one session simultaneously opened against different targets, using different syntaxes and schemas. You can even launch the same query on several sessions at a time, receiving responses in parallel.
ZNavigator allows the use of "simple queries", constructed as a series of terms joined together by a default operator. On the other hand, queries of unlimited complexity can be constructed either manually, using a Prefix RPN query syntax, or by means of a "fill in the blanks" Query Builder.
Queries, record listings or full record contents can be transferred to other applications via the clipboard or using the "export" facility, or can be stored in private "folders" for future use. A history facility makes it easy to return to a previous query. If the server supports this functionality, you can use the results of a previous query as part of a new one using the previous result set.
ZNavigator supports a wide variety of record syntaxes, including SUTRS, several MARC formats and GRS-1, which should be the de-facto standard in the next few years. ZNavigator supports and translates General, Meta and Private Tags, and adapts dynamically to Z39.50 registered external Schemas such as GILS.
ZNavigator may act as a "gateway" for external applications to the Z39.50 world: ZNavigator is a DDE server supporting a set of simple commands to open sessions, launch searches or retrieve records. Both headings lists and full records can be received through DDE items. Custom applications can be easily constructed for specialised purposes using any platform that supports DDE. For instance, you can create an Excel macro that, talking to ZNavigator, opens a session to a Z39.50 server, launches a search, retrieves the first 20 record headings, inserts them into a spreadsheet area and performs some calculations on the values retrieved. The full power of Z39.50 is therefore available.