ColdFusion, made by Allaire, is a popular and sophisticated set of products for building Web sites and serving pages to users. With ColdFusion, a company can build a content database using input templates and combine these with application programs to create a Web site in which pages are developed dynamically as they are served. ColdFusion consists of ColdFusion Studio, which is used to build a site, and ColdFusion Server, which serves the pages to users. ColdFusion Studio is described as "a complete integrated development environment (IDE)" and ColdFusion Server as "a deployment platform." The most valuable feature for many companies that use ColdFusion is the ability to build Web sites as "piece parts" that can be stored in a database and then reassembled for Web pages, e-mail newsletters, and other uses. ColdFusion provides a visual interface for building Web pages directly or for building the "piece parts." For example, a newspaper with a Web site can have a reporter enter a story, dateline, author, and other information, using a text entry form free of all Web page formatting and structure details or language tags. (The newspaper uses ColdFusion to design the forms and to define the database.) The content entered by the reporter is later gathered and formatted into a Web page when it is requested. The reporter is free from having to understand HTML and other details. ColdFusion is also a popular tool for building e-commerce sites.

ColdFusion has its own page markup language, called ColdFusion Markup Language (CFML). CFML encompasses the Web's Hypertext Markup Language HTML and Extensible Markup Language (XML). A just-in-time (JIT) compiler turns the CFML into the pages that get served. Allaire emphasizes that their product set is open and "extensible." Applications can access databases using Microsoft's OLE DB, ODBC, or drivers that access Oracle and Sybase databases. ColdFusion can be coordinated with distributed applications that use CORBA or Microsoft's DCOM to interact with other network applications.

Allaire also says that ColdFusion is scalable, allowing both the size of a database and the number of users that can be served to grow. For large Web sites, multiple ColdFusion servers can be run together as a cluster.