For something designed to (among other things) reduce the heat inherent to high-density server farms, it is slightly ironic that server blades have become the hottest item in the server world. In the past year, this developing technology has created a strong market for itself with vendors springing up whose entire strategy evolves around a blade-based product line (as in the case of RLX and Egenera) and other vendors that have created blade-based lines of business (as is the case of a Intel and Compaq).

During the past several years, the Internet has changed the course of server usage from single, carefully placed servers (consider the history of mini- and mainframe computers) to installations of multiple servers or high-density server farms. The PC revolution has also been part of this change, which has seen many large centralized computers replaced by numerous, much less expensive servers based on PC technology.

Cost has always been a big factor in this change, but the Internet accelerated the use of multiple servers to handle the scalability, redundancy, reliability, and performance that heavily trafficked Web sites require.

Today, many organizations find the concepts behind using large numbers of servers compelling even while finding the reality difficult. Amassing servers has a physical aspect wherein a lack of space, high heat, and complex cabling are serious problems. Then too, there are problems associated with securing, managing, and coordinating a large number of servers.

All of which, of course, in the end adds up to cost.