TPF is a real time operating system created by IBM for mainframes descended from the IBM System/360 family, including zSeries and System z9. The name is an initialsim for Transaction Processing Facility.
TPF evolved from the Airlines Control Program (ACP), a free package developed in the mid-1960s by IB M in association with major North American and European airlines. In 1979, IBM introduced TPF as a replacement for ACP — and as a priced software product. The new name suggests its greater scope and evolution into non-airline related entities.
Current users include Sabre (reservations), Amadeus (reservations), VISA Inc. (authorizations), American Express (authorizations), EDS SHARES (reservations), Holiday Inn (central reservations), Singapore Airlines, KLM/Air France, Amtrak, Marriott International, Travelport snf the New York Police Department (911 system).
TPF delivers fast, high-volume, high-throughput transaction processing, handling large, continuous loads of essentially simple transactions across large, geographically dispersed networks. The world's largest TPF-based systems are easily capable of processing tens of thousands of transactions per second. TPF is also designed for highly reliable, continuous (24x7) operation. It is not uncommon for TPF customers to have continuous online availability of a decade or more, even with system and software upgrades. This is due in part to the multi-mainframe operating capability and environment.
While there are other transaction processing systems, notably IBM's
own CICS and IMS, TPF's raison d'Ítre is extreme volume, large
numbers of concurrent users and very fast response times.
ALCS, which stands for Airline Control System, like TPF is also a product of IBM. It is an application server that provides industrial-strength, online transaction management for mission-critical applications.
ALCS is a transaction processing monitor for the IBM System/360,
System/370, ESA/390 and zSeries mainframes. It is a variant of TPF
specially designed to provide all the benefits of TPF (very high speed,
high volume, and high availability in transaction processing) but with
the advantages such as easier integration into the data center offered
by running on a standard IBM operating system platform. It is also
known as TPF/MVS.
Like TPF, it is primarily used in the airline, hotel, and finance industries.
Whereas TPF runs as a stand-alone OS, ALCS is designed to run as an application on top of MVS, OS/390 and z/OS. However, the API it provides to applications is very similar to that on TPF, so applications written for TPF can run on ALCS with minimal modifications: typically fewer modifications than are required to move from one release of TPF to another. ALCS 2.3.1 runs on OS/390 2.10 and z/OS. ALCS 2.4.1 was released in June 2008.Because it runs under standard IBM operating systems, it can easily leverage other developments or enhancements on those platforms. For example, to enable MQSeries for TPF required the porting, modification, and authoring of large volumes of code. To enable this on ALCS, only an interface to the MQ product on z/OS needed to be written. And any enhancements made to MQ Series on z/OS by the MQ team are available without any additional work on the part of the ALCS development team.