An application server within a fully integrated development

Pervasive Software was one of the first companies to offer an integrated development environment for its application server. Even in the face of competition from heavyweights like IBM, Netscape, and Oracle, subsequent versions of Tango have managed to not only compete but also remain among the best. The current version of Tango 2000 Application Server and Development Studio is no exception, and is one of the first application servers to exploit XML for data manipulation as well as to store its own application files.

Even in the face of competition from heavyweights like IBM, Netscape, and Oracle, subsequent versions of Tango have managed to not only compete but also remain among the best.

The Tango 2000 Application Server runs on all major operating systems (Windows NT/2000, Solaris, Linux, and MacOS), an advantage that cannot be claimed by most other application servers. Along with this flexibility, the Tango server is among the leaders in scalability. We configured a three-server arrangement and found its management features, especially the new ones such as Server Watcher and Load Splitting Client, to be very effective. Working alongside the application server is another new feature, the Tango Web Analyzer. Tango Web Analyzer is a suite of components to monitor Web site activity. What makes this configuration interesting is its capability to integrate Analyzer output, such as user preference activity, directly into an application.

As a plug-in (NSAPI or ISAPI) or through CGI, Tango Application Server works with a Web server to create dynamic HTML pages. The Tango server in turn uses Tango application files (now in XML format, which can be edited outside of Tango) to code business logic, database connectivity, and presentation layout for the application. The application files are generated within the Tango Editor of the Development Studio, a complete and relatively user friendly drag-and-drop environment.

What makes the Tango Development Studio unique to work with is its application development model. Using this model, the product builds applications in layers. It has: a Database Logic Layer to interface with data sources (usually in SQL), a Business Logic Layer where most business rules are coded and bound to COM or JavaBeans, and a Presentation Layer with text and graphics expressed in HTML, DHTML, or PDF. As users work in the visual editor, almost everything they do is represented as objects and actions. Actions are precoded routines that help express the relationships between objects. Each layer is clearly presented by icons, as are the related actions (e.g., Create Object Instance, File, and Mail). Although it may take a while to learn this approach, and it does not cover all the bases in user interface development, a great deal of application development can be accomplished without traditional programming.

Especially when used in conjunction with the bundled companion product, Pervasive.SQL 2000, Tango 2000 is good at connecting to a wide variety of database sources. This includes ubiquitous ODBC support and a direct driver for Oracle. Tango provides two “builders” (wizard-like routines with a good deal flexibility) for developing database searches and manipulating records that for the most part make it unnecessary to code with the Tango meta-tags (extensions to HTML).

While it is true that buying into the Tango approach ties an organization to a particular company, Tango provides some of the best out-of-the-box cross-platform capability, and it successfully straddles the Microsoft and Java worlds — no mean feat. Other application servers may have areas of strength, such as load balancing or CORBA connectivity that surpass Tango. However, few can match its overall flexibility. Thus, as a combination, Tango 2000 Application Server and development environment belong on the “must evaluate” list of any organization developing Web applications.

Pros: 7 Excellent cross platform capability, 7 Tango Actions encapsulate much routine programming and the development model (once learned) should shorten development cycles

Cons: 7 Limited user interface development

Operating Systems / Latest Versions:

Application Server: Windows NT/2000, Solaris, Linux, and MacOS
Developers Studio: MacOS and Windows