The problem with application servers, according to one analyst, is that just about everyone has one. And because there are so many coming from different angles, it becomes difficult to define the category.

Everything from traditional middleware products to new-generation Web development tools are being hawked as application servers, said e-Business technology infrastructure service research director Mark Driver of Gartner Group Inc. in Atlanta, Ga.

“It’s caused a considerable amount of confusion,” Driver said. “The term ‘application server’ is being pushed down into the plumbing.”

Application servers are the middle tier in a three tier solution. They sit between the thin client on the front end and a database on the back end. The business logic can be placed in the application server.

“Essentially, it moves the complexity from countless amounts of thin clients back to the middle tier,” said Danica Pravica, a senior marketing manager for server technologies at Oracle Corp. in Mississauga, Ont.

To deal with the many application servers that are cropping up, the Gartner Group has divided them into two categories – systematic and opportunistic application servers. The systematic app servers tend to take longer to develop against because they don’t have a complete development infrastructure out of the box. They’re also more run-time oriented, more expensive and come from traditional middleware vendors. Often, they have a full-blown transaction processing facility built into them.

“They’re the kinds of tools that you tend to run very mission-critical types of applications out of,” Driver said.

At the other end of the continuum are app servers that are designed for quick delivery and a rapid application development environment. Gartner calls them opportunistic app servers because they are generally bought by users who are looking for a quick e-commerce or e-business solution, but are not ready to make a long-term commitment to the vendor, Driver said.

What’s common to all types of application servers is that more and more of them are starting to offer e-business solutions.

“The number one trend that we’re seeing right now is it’s no longer good enough to be an application server. We’re finding that most app server companies are tending to position themselves in the e-business platform,” Driver said.

Users today are looking for application servers that go beyond the simple application server infrastructure and offer such features as content management, search capabilities and personalization either out of the box or as value-added components.

“We consider application servers to be at the core of the Internet-based solutions that we’re going to see over the next five years,” said International Data Corp. (IDC) application development and deployment program director Steve Garone.

Users will be looking for app servers that have features such as portal capabilities and security, which will allow them to be used as the foundation for e-commerce and e-business solutions, Garone said.

IDC studies indicate that the app server market, which was at about US$4.6 million in 1998, is expected to grow to US$2.36 billion by 2003, an average annual growth rate of 39.1 per cent.

Citizenship and Immigration Canada has automated over 4,000 business rules on their Ottawa-based Sybase Canada Ltd. application server. Employees use the system to track their cases from beginning to end when a claimant is either given landed status or sent back to their country of origin.

Because the organization has a worldwide presence, they decided on an Internet-based solution, said Citizenship and Immigration Canada business systems development director Frank Brown in Ottawa.

Users access the case management system through a Netscape browser, making deployment easy.

“This stuff is so cheap to deploy, it’s almost free,” Brown said. “We get the added advantage that you keep the database in one place where it’s centrally accessible.”

In a stress test with 500 users only about 4 per cent of the processing power of the middleware was used, Brown said.

“And the application server is incredibly efficient,” he said.