individually or aggregated either on the chassis or through other blades. The ability to boot the blade from a storage area network (SAN) allows for an entirely disk-free blade, an example of which implementation is the Intel Modular Server System. Other blades Since blade enclosures provide a standard method for delivering basic services to computer devices, other types of devices can also utilize blade enclosures. Blades providing switching, routing, storage, SAN and fibre-channel access can slot into the enclosure to provide these services to all members of the enclosure. Systems administrators can use storage blades where a requirement exists for additional local storage. Uses Blade servers function well for specific purposes such as web hosting, virtualization, and cluster computing. Individual blades are typically hot-swappable. As users deal with larger and more diverse workloads, they add more processing power, memory and I/O bandwidth to blade servers. Although blade-server technology in theory allows for open, cross-vendor systems, most users buy modules, enclosures, racks and management tools from the same vendor. Eventual standardization of the technology might result in more choices for consumers; increasing numbers of third-party software vendors have started to enter this growing field. Blade servers do not, however, provide the answer to every computing problem. One can view them as a form of productized server-farm that borrows from mainframe packaging, cooling, and power-supply technology. Very large computing tasks may still require server farms of blade servers, and because of blade servers' high power density, can suffer even more acutely from the heating, ventilation, and air conditioning problems that affect large conventional server farms. History Developers first placed complete microcomputers on cards and packaged them in standard 19-inch racks in the 1970s, soon after the introduction of 8-bit microprocessors. This architecture was used in the industrial process control industry as an alternative to minicomputer-based control systems. Early models stored programs in EPROM and were limited to a single function with a small real-time executive. The VMEbus architecture () defined a computer interface that included implementation of a board-level computer installed in a chassis backplane with multiple slots for pluggable boards to provide I/O, memory, or additional computing. In the 1990s, the PCI Industrial Computer Manufacturers Group PICMG developed a chassis/blade structure for the then emerging Peripheral Component Interconnect bus PCI called CompactPCI. CompactPCI was actually invented by Ziatech Corp of San Luis Obispo, CA and developed into an industry standard. Common