Application Server Software Platforms

Application server software platforms supply at least the minimum set of services required to deploy interoperable components, in the coarsest sense of that word, as coherent applications. ASSP products act in the logical middle tier of a distributed multiple-tiered environment of clients, back-end applications code, and data sources. The minimum set of services (using that word in a computer science sense) includes the following on an integrated basis:

• Security
• A single and well-defined developer interface
• Runtime load balancing
• Data persistence

ASSPs are distinguished from traditional point-to-point unifunctional middleware, integration server software platforms, and databases in the following ways:

• ASSPs provide a centralized focus for integration; support for the development and deployment of in-house-developed, custom-built, and packaged software components; and a level of abstraction beyond the capabilities of point-to-point middleware products.
• ASSPs address the entire application, as opposed to the schema or DLL focus of databases.

In various combinations with other application deployment software products, or alone, ASSP products perform one or more of the following functions:

• Front-end concentration
• Point-to-point application interoperability (so-called A2A)
• Portal and HTTP serving (but not portal serving on a standalone basis; see the EIP market)
• Integration of collaborative/transaction/analytic application logic to structured/unstructured data
• Support for so-called edge devices such as RFID tags, particularly in support of mobile computing
• Various types of intersystem transaction management, including clustering support and two-phase commit support

Some computer science definitions refer to one of the tiers in a classic three-tier client/server architecture as the application server (along with user interface [UI] and database), but this definition is much narrower, especially in its inclusion of both a specific developer interface and runtime functionality. The following are representative of the more than 100 vendors and products we follow in this market:

• Adobe Macromedia JRun and ColdFusion
• Apache HTTP Server (Because it is open source and is basically distributed as part of many suppliers' application deployment software products, Apache.org does not appear as a vendor in our database; however, Apache usage is measured when we are looking at other metrics and the revenue realized from maintaining Apache HTTP server shows up in various vendors' software revenue calculations.)
• BEA Systems WebLogic Application Server and WebLogic Platform (The measurement of the Platform as an ASSP is an example of our deciding that ASSP is the Platform's predominant market; it could also have been measured in ISSP, but we would not try to divide its revenue stream between the two.)
• Borland Enterprise Server products
• IBM Websphere Application Server (all editions and operating systems)
• Jonas Application Server (The product itself is open source; therefore, only its maintenance-stream revenue within Red Hat and elsewhere is included in the SMF database.)
• Oracle Container for J2EE (OC4J)