Link-Resolver Products

Although Ex Libris's SFX was the first commercially available link resolver, the market now offers many other products, including other commercial and homegrown products as well as open-source releases. Choosing a link resolver can be a daunting task, so simply knowing the available options can be useful to those wishing to purchase, build, or adapt an open-source link resolver. This section is not meant to be comprehensive but rather includes the most popular link-resolver products and options.

Commercial

Commercial link resolvers are available from a number of vendors, including integrated library system (ILS) vendors as well as other content providers, such as Serials Solutions, Ovid, and EBSCO. In October 2004, Grogg and Ferguson published an article in Computers in Libraries that offered a large-scale comparison of commercially available link resolvers, including a detailed comparison chart of features to consider when evaluating possible purchases. These features included:

* Remote or local hosting;

* Subscription or purchase;

* Title listing availability;

* Customization of the link-resolver menu of services/ intermediary screen;

* Customization of extended services;

* Usage statistics;

* Citation-finder feature;

* User support group;

* Web-based administrative tools;

* Ability to "invoke" or go directly to the full text, bypassing the link-resolver menu of services/ intermediary screen;

* Ability to specify/weight the order of links in the link-resolver menu;

* Ability to block links from appearing in the menu or prevent circular linking;

* Ability to add targets and sources; and

* Consortia or individual purchases.1

Another more qualitative feature to consider is the quality of the vendor's global knowledgebase. Because the knowledgebase powers the link resolver's ability to match the user to his or her desired information object, the knowledgebase needs to be as correct, comprehensive, and up to date as possible. This can be difficult to ascertain, but length of time the product has been on the market as well as whether or not the vendor maintains its own knowledgebase (or buys content from elsewhere) are two important factors to consider.

Also, it is important to know the scope of the knowledgebase, including whether or not the vendor tracks non-journal content (e-books and Web sites) as well as open-access materials. Additionally, if a library is currently using a stand-alone A-to-Z listing service (such...