Ad hoc integration of Web Services

"The Unix idea of piecing together solutions from reusable parts has morphed into XML-based, service-oriented architecture. This time around, though, it's all happening on the Web, in an environment where everybody can compose simple and popular tunes. When technologists forget that, I hope users will administer the dope slap we deserve." Jon Udell on XML.com

This resonated with me. Recently, as part of my work at a London University, I re-engineered a legacy enterprise-wide web application called MISLine, moving it from a straightforward ColdFusion app into a set of Java Beans / servlets / JSPs and deploying it in a J2EE cluster. MISLine is a homemade web-interface layered over a proprietry student record sytsem. Rather late in the re-development, I decided to turn MISLine into a REST application. This has already started to pay off as other systems can use some of the functionality of this application: just compose the correct URL and get an XHTML document back. As the application was producing this anyway, going the REST route cost little extra development, but has allowed all kinds of 'accidental' integration between systems.

Elsewhere, Jon Udell claims that "RESTful systems enable ad-hoc integration". I am already aware that some users in my University are using MISLine URLs which encapsulate a particular query, such as getting a list of students for a given course, and including these URLs as hyperlinks in their own web pages, adding a dynamic information lookup capability to a static website. The important point here, is that a measure of web-application integration has been achieved by someone who knows nothing about web-application development but who can use the University's Content Management System.