Editing IBM mainframe (section)

==Today's systems==
{{main|IBM Z}}

[[File:Z800 2066 JKU.jpeg|thumb|right|IBM System z800]]

The [[IBM Z]] family, introduced in 2000 with the z900, supports [[z/Architecture]], which extends the architecture used by the System/390 mainframes to 64 bits.

===Processor units===
The different processors on current IBM mainframes are:
* CP, [[central processor]]: general-purpose processor
* IFL, [[Integrated Facility for Linux]]: dedicated to [[Linux]] OSes (optionally under [[z/VM]])
* ICF, Integrated [[Coupling Facility]]: designed to support [[IBM Parallel Sysplex|Parallel Sysplex]] operations
* SAP, System Assist Processor: designed to handle various system accounting, management, and [[I/O channel]] operations
* [[zAAP]], System z Application Assist Processor: currently limited to run only [[Java (programming language)|Java]] and [[XML]] processing
* [[zIIP]], System z Integrated Information Processor: dedicated to run specific workloads including [[IBM Db2]], [[XML]], and [[IPSec]]

These are essentially identical, but distinguished for software cost control: all but CP are slightly restricted{{efn|All supported IBM operating systems test the type of processor they are running on and restrict usage in accordance with license terms.}} such they cannot be used to run arbitrary operating systems, and thus do not count in software licensing costs (which are typically based on the number of CPs).<ref>{{cite web|url=http://publib.boulder.ibm.com/infocenter/zos/basics/topic/com.ibm.zos.zmainframe/zmainframe_book.pdf|title=Mainframe concepts (page 31)|author=IBM corp.|year=2005|access-date=May 5, 2012|archive-date=July 8, 2012|archive-url=https://web.archive.org/web/20120708195859/http://publib.boulder.ibm.com/infocenter/zos/basics/topic/com.ibm.zos.zmainframe/zmainframe_book.pdf|url-status=live}}</ref>
There are other supporting processors typically installed inside mainframes such as [[cryptographic]] accelerators ([[CryptoExpress]]), the [[OSA-Express]] networking processor, and [[FICON]] Express disk I/O processors.

Software to allow users to run "traditional" workloads on zIIPs and zAAPs was briefly marketed by Neon Enterprise Software as "zPrime" but was withdrawn from the market in 2011 after a lawsuit by IBM.<ref>{{cite web|last=Radding|first=Alan|title=Bye bye zPrime on System z|date=June 6, 2011|url=http://dancingdinosaur.wordpress.com/2011/06/06/bye-bye-zprime-on-system-z/|publisher=DancingDinosaur|access-date=May 5, 2012|archive-date=June 30, 2012|archive-url=https://web.archive.org/web/20120630214501/http://dancingdinosaur.wordpress.com/2011/06/06/bye-bye-zprime-on-system-z/|url-status=live}}</ref>

===Operating systems===
The primary [[operating system]]s in use on current IBM mainframes include [[z/OS]] (which followed [[MVS#MVS/ESA|MVS/ESA]] and [[OS/390]] in the [[OS/360 and successors|OS/360]] lineage), [[z/VM]] (which followed [[VM (operating system)|VM/ESA]] and VM/XA SP in the [[CP/CMS|CP-40]] lineage), [[z/VSE]] (which is in the [[DOS/360 and successors|DOS/360 lineage]]), [[z/TPF]] (a successor of Transaction Processing Facility in the [[Airlines Control Program]] lineage), and [[Linux on IBM Z]] (e.g., [[Debian]], [[Red Hat Enterprise Linux]], [[SUSE Linux Enterprise Server]]). Some systems run [[MUSIC/SP]], as well as [[UTS (Mainframe UNIX)]]. In October 2008, Sine Nomine Associates introduced [[OpenSolaris on System z]]; it has since been discontinued.

===Middleware===
Current IBM mainframes run all the major enterprise [[transaction processing]] environments and [[database]]s, including [[CICS]], [[Information Management System|IMS]], [[WebSphere]] Application Server, [[IBM Db2]], and [[Oracle Database|Oracle]]. In many cases these [[software]] subsystems can run on more than one mainframe operating system.

===Emulators===
There are software-based emulators for the System/370, System/390, and System z hardware, including [[FLEX-ES]], which runs under [[UnixWare]] or [[Linux]],<ref>{{cite web|url=http://www.funsoft.com/technical.html|title=Technical Overview: FLEX-ES|access-date=May 8, 2015|archive-date=May 18, 2015|archive-url=https://web.archive.org/web/20150518070835/http://www.funsoft.com/technical.html|url-status=live}}</ref> and the freely available [[Hercules (emulator)|Hercules]], which runs under [[Linux]], [[FreeBSD]], [[Solaris (operating system)|Solaris]], [[macOS]] and [[Microsoft Windows]].
IBM offers an emulator called zPDT (System z Personal Development Tool) which runs on Linux on [[x86-64]] machines.<ref>{{cite web|url=https://www-304.ibm.com/partnerworld/wps/servlet/ContentHandler/pw_com_zpdt|title=IBM System z Personal Development Tool|publisher=IBM|access-date=January 27, 2016|archive-date=March 4, 2016|archive-url=https://web.archive.org/web/20160304051831/https://www-304.ibm.com/partnerworld/wps/servlet/ContentHandler/pw_com_zpdt|url-status=live}}</ref>