Shruthi Rajegowda'
December 10, 2008


PLTScheme is implemented in Webservlet application to develop a user-interactive continuation based web framework. The webpage is similar to Facebook, Orkut and called Scheme Orkut which has a main page -My Scrapbook wherein the user can enter message or scraps and it is displayed on the screen similar to any online chat community


Concepts Demonstrated

Symbolic representation such as Quasiquotation is used in parser. Mutable list strucuture is used for displaying all the messages in the page. New messages or comments added are displayed on the web page using append procedure. Binding procedures such as request-bindings are used to extract the value the user enters.

External Technology

PLTScheme Webservlet is a framework for webpage applications that make the coding simple and easy to understand. The main advantage in Scheme is continuation where the frames can be connected with each other. It is thus a suitable candidate for this Web application project. "When a web browser visits scheme application’s URL, the browser constructs a request structure and sends it off to web application. The start function in scheme will accept requests and produce responses. The send/suspend/dispatch function in web server library allows creating URLs that direct to different parts of our application."


The Webpage serves the basics of online chat community and helps to communicate with family or friends. This user interactive feature of instant messaging doesn’t need any messenger downloads.

Technology Used Block Diagram

Additional Remarks

Scheme webservlet application is simple and can be extended in development of any website with less hassle compared to lengthy and complicated HTML codes or JSPs. However, secure data transfer issues need to tackled. PLTScheme version 4.1.3 contains much better documentation for developing Scheme servlets as well as an "instant servlet" language. "With the instant servlet language you can quickly develop and test servlets on your own machine without installing and configuring the PLT webserver." The sentences within quotes" "are taken from PLT online documentation on WebServlet.