Wikipedia
SISCweb is a framework to facilitate writing stateful Scheme web applications in a J2EE environment.
By using continuations, SISCweb does away with the page-centric execution model typical of web programming. Every time the program sends a response to the browser, its state is suspended, to be then resumed from that exact point when the browser submits a request.
One implication of this approach is that local variables in scope when the response is sent will still be in scope when the subsequent request is received, making much of the session-object data shuffling needless. Another consequence is that, much like in console-based applications, the conversational state between client and server is constantly maintained—hence the term "stateful."
SISCweb is implemented in SISC, a Scheme interpreter for the JVM with support for full continuations.