Editing Mainframe computer (section)

==Current market==
[[IBM]], with the [[IBM Z]] series, continues to be a major manufacturer in the mainframe market. In 2000, [[Hitachi]] co-developed the [[zSeries]] z900 with IBM to share expenses, and the latest Hitachi AP10000 models are made by IBM. [[Unisys]] manufactures [[Burroughs large systems|ClearPath Libra]] mainframes, based on earlier [[Burroughs MCP]] products and ClearPath Dorado mainframes based on [[UNIVAC|Sperry Univac]] [[OS 2200|OS 1100]] product lines. [[Hewlett Packard Enterprise]] sells its unique [[NonStop (server computers)|NonStop]] systems, which it acquired with [[Tandem Computers]] and which some analysts classify as mainframes. [[Groupe Bull]]'s [[General Comprehensive Operating System|GCOS]], [[Stratus Technologies|Stratus]] [[OpenVOS]], [[Fujitsu]] (formerly Siemens) [[BS2000]], and Fujitsu-[[ICL VME]] mainframes are still available in Europe, and Fujitsu (formerly Amdahl) [[Amdahl Corporation|GS21]] mainframes globally. [[NEC]] with [[Advanced Comprehensive Operating System|ACOS]] and Hitachi with AP10000-[[Hitachi VOS3|VOS3]]<ref>[http://www.hitachi.co.jp/AP/ Hitachi AP10000 - VOS3]</ref> still maintain mainframe businesses in the Japanese market.

The amount of vendor investment in mainframe development varies with market share. Fujitsu and Hitachi both continue to use custom S/390-compatible processors, as well as other CPUs (including POWER and Xeon) for lower-end systems. Bull uses a mixture of [[Itanium]] and [[Xeon]] processors. NEC uses Xeon processors for its low-end ACOS-2 line, but develops the custom NOAH-6 processor for its high-end ACOS-4 series. IBM also develops custom processors in-house, such as the [[IBM Telum|Telum]]. Unisys produces code compatible mainframe systems that range from laptops to cabinet-sized mainframes that use homegrown CPUs as well as [[Xeon]] processors. Furthermore, there exists a market for software applications to manage the performance of mainframe implementations. In addition to IBM, significant market competitors include [[BMC Software|BMC]]<ref>{{cite web|title=BMC AMI Ops Automation for Data Centers|url=https://www.bmc.com/it-solutions/bmc-ami-ops-automation-data-centers.html|website=[[BMC Software]]|access-date=March 13, 2023}}</ref> and [[Precisely (company)|Precisely]];<ref>{{Cite web|title=IBM mainframe solutions {{!}} Optimizing your mainframe|url=https://www.precisely.com/solution/ibm-mainframe-solutions|access-date=September 23, 2022|language=en-US}}</ref> former competitors include [[Compuware]]<ref>{{cite web|title=Mainframe Modernization|url=http://www.compuware.com/mainframe-solutions/workbench-mainframe-modernization.html|access-date=October 26, 2012}}</ref><ref>{{cite web|title=Automated Mainframe Testing & Auditing|url=http://www.compuware.com/en_us/mainframe-solutions/products/hiperstation-automated-mainframe-testing.html|access-date=October 26, 2012}}</ref> and [[CA Technologies]].<ref>{{cite web|title=CA Technologies|url=https://www.ca.com/us/why-ca/mainframe.html}}</ref> Starting in the 2010s, [[cloud computing]] is now a less expensive, more scalable alternative.{{Citation needed|reason=This depends on a lot of factors and is debatable|date=September 2024}}