The Cornell Web Lab Collaboration Server is a suite of tools and services for GUI-based extraction, analysis and sharing of archived web data. See http://weblab.infosci.cornell.edu/ and http://www.cs.cornell.edu/~weigel for details about the project.
JLog is a Prolog interpreter written in Java. It is fast and perfectly suited for education. It includes source editor, query panels, online help, animation primitives, and a GUI debugger. JScriptLog is Prolog in JavaScript.