New Java Toolkit Helps Bring Virtual Fish Tank to Life

In June, the Computer Museum in Boston unveiled a spectacular new exhibit: a 2,200-square-foot virtual fish tank, filled with hundreds of three-dimensional, artificially intelligent sea creatures. The tank is displayed on 12 screens, each run by an individual computer. Museum visitors can even interact with the fish through seven touch screens, each run by its own computer.

When Nearlife Inc. (Cambridge, Mass.,, the company that designed the exhibit in conjunction with the museum and the MIT Media Lab, began working on the project late last year, they had to find a way to share information about the creatures' locations and behaviors between all of those computers, according to Tinsley Galyean, Nearlife's president. Since they had already decided to develop the application using Java, they turned to Sun Microsystems Inc.'s Java Shared Data Toolkit (JSDT) to solve their problem.

"JSDT transmits information between the computers to let them know that a fish has swum from one screen to another," Galyean explains. "Without JSDT, we would have had to write our own significantly smaller subset of what JSDT did."

In August, Sun made the JSDT publicly available. For developers who aren't working on their own virtual fish tank, JSDT can also be used to create Java-based applications that share data, including chat forums, shared applications such as collaborative whiteboards and remote presentations.

Applications using JSDT are very diverse, although most aren't quite as interesting as the Virtual FishTank, according to Nanette Simpson, senior engineering manager for Java media at Sun. "More mundane things are automating forms processing, distance learning, chat rooms and whiteboards," she says. "The applications we would like to see developed are enterprise applications."

In addition to the code libraries, the kit includes four sample applications built using the JSDT: a chat program, a shared whiteboard, a stock quote viewer and a sound server for shared audio. The toolkit costs $99 and can be downloaded from