Lipman defends MS thesis on in-browser client and server web application framework

On November 15, 2011, Computer Science graduate student Derrell Lipman successfully defended his Master's thesis, entitled “LIBERATED: A fully in-browser client and server web application debug and test environment.”

Lipman’s research focused on addressing the challenge of developing client-server web systems.

He observed that traditional web-based client-server application development is accomplished in two separate pieces. There is a front-end portion which runs on the client machine, and a back-end portion which runs on the server machine. Typically, the front-end component is coded in HTML and JavaScript, while the back-end is written in PHP,, or some another language that can interface to a database.

The skill sets required for these two pieces are different. Often, the front-end and back-end are developed and tested completely independently, based purely on an interface specification.

Lipman addressed this by developing his framework, LIBERATED, which stands for “Lipman’s In-Browser EnviRonment for Application TEsting and Development.”

In the thesis, Lipman proposed a new methodology for web-based client-server application development, in which a simulated server is built into the browser environment to run the back-end code.

This design allowed the front-end code to issue requests to the back-end in either a synchronous or asynchronous fashion, and single-step, using a debugger, directly from front-end code into back-end code, thereby completely testing both components with the desktop browser environment.

In Lipman’s system, that exact same back-end code, now fully tested in the simulated environment, is then recompiled and moved to a real server.

In the defense, Lipman presented the detailed design of LIBERATED, and described how he used it to develop the App Inventor Community Gallery, a web system created for users of Google’s App Inventor programming environment for Android phones to share their projects.

Prof. Fred Martin served as Lipman’s thesis adviser, and Dr. Mark Sheldon served as his thesis reader. Lipman’s research was supported by a grant from Google.

A copy of the thesis is available at

Block diagram of the LIBERATED architecture. The programmer uses JavaScript and the qooxdoo framework to code both the frontend and back pieces of the client-server system. The backend runs in a simulated environment in the developer’s browser, and when completed, is moved to a separate server machine. The same backend code is run in both places.

About this Entry

This page contains a single entry by Martin, Fred published on December 1, 2011 10:25 PM.

Senatillaka and Choudhary each win prize finishes at Boston Startup Weekend was the previous entry in this blog.

Penta defends MS thesis on video game creation for mathematical learning is the next entry in this blog.

Find recent content on the main index or look in the archives to find all content.

Subscribe to feed Subscribe to this blog's feed