The Web is a compelling platform for database-driven, interactive applications. It is platform independent, provides instant global access, and significantly lowers deployment and training costs. In search of these benefits, many organizations are building Web applications or moving existing client/server applications to the Web.
Until recently, there were few organizations building commercial Web/database applications because of the lack of development tools. Applications had to be custom coded in PERL or C++. As tools that lower the cost of application development and maintenance mature, organizations are increasingly turning to the Web as a platform for commercial applications.
We will now look at some tools for developing Web applications.
22.5.1 Javamatic
Javamatic is a tool for adding a Web-based interface to a command-line driven system. Javamatic generates a graphical user interface, then invokes commands in the legacy system transparently to the user. The user interface is generated from a high level description of the application, which is User Interface (UI) independent, combined with a set of UI mapping rules. The application is wrapped with an interface server; thus multiple clients can use the application through the Web. Javamatic was developed as part of my thesis at Virginia Tech.
Javamatic was originally written to reduce the time spent to design, develop, and maintain interface code in a statistical system called Chitra, a system to visualize, statistically analyze, and model traces of data. Chitra is composed of several small commands which are command-line driven. Every time a new command was added to the system, the interface had to be manually updated. This caused the interface to be inconsistent and difficult to maintain. Also, Chitra only runs on a UNIX system and requires a high-end workstation to operate efficiently. With Javamatic we were able to reduce the time needed to update the interface and make the system widely accessible to any user with a Java capable Web browser.
WebObjects is a tool designed to help corporations develop dynamic, server-based applications for the World Wide Web. These dynamic applications can be deployed on corporate Intranets or to the global Internet. WebObjects is developed by NeXT.
WebObjects is designed to preserve investments in existing computing resources. Using NeXT's technology, Web applications can be easily integrated with legacy technology and data spanning the entire computing environment, from the desktop to the mainframe. WebObjects is also an open technology, supporting all major Web standards, browsers, HTTP servers, scripting languages (e.g. Java, Perl), with the ability to embrace new technologies as they evolve. Robust Web applications must provide reliable, secure, and stable processing under heavy demands, all these issues are addressed by WebObjects.
NetDynamics is a next generation application builder from Spider Technologies. The NetDynamics application builder integrates visual development, a high performance Java server, and scalable database access into an open, robust architecture optimized for rapid delivery of commercial grade applications. The NetDynamics development tool provides rapid application development, tight integration with Java as the application development language, an open environment, and support for security, session and state, and transaction management.
Castanet is a suite of tools and technologies for efficiently deploying rich content and applications over the Internet. Using Castanet, developers, publishers, and entertainment companies can deploy a new generation of applications that are unrestrained by browser GUIs, limited network bandwidths or computer platforms. Castanet was developed by Marimba, Inc.
Castanet channels (applications) eliminate many of the weaknesses that have kept applets from replacing applications [Marimba96]. Channels can save state on the user's disk and send that state back to channel developers. Channel software is mirrored, rather than cached, thus it operates as quickly and reliably as conventional applications.
Bongo, also developed by Marimba, is a visual tool for designing and implementing GUIs for Java applications. Bongo can be used to create modular interface building blocks called presentations. Presentations are GUI element assemblies that encourage reuse, consistency, and the division of GUI design among the members of a development team.
Copyright © 1996 Constantinos Phanouriou, All Rights Reserved
Constantinos Phanouriou
<phanouri@vt.edu>
Last modified: Fri Nov 26 10:00:00 1996