The HP NonStop (originally Tandem) timeline spans over 50 years of evolution in fault-tolerant computing, beginning with the vision of James Treybig and transitioning through several major corporate owners. 

Founding and Initial Growth (1974–1980s)

• 1974: Tandem Computers Incorporated is founded by James (Jimmy) Treybig in Cupertino, CA.
• 1976: The first NonStop I (T/16) servers are shipped to Citibank, introducing the “fail-fast” architecture.
• 1981: NonStop II is introduced, adding 32-bit addressing support to the 16-bit registers.
• 1983: NonStop TXP (Tandem Extended Processor) debuts, featuring the first use of cache memory and a native Transaction Monitoring Facility (TMF).
• 1986: NonStop VLX (Very Large eXtension) is released, introducing 32-bit data paths and the first fault-tolerant SQL database, NonStop SQL.
• 1987: NonStop CLX is launched as a low-cost, office-ready minicomputer system.
• 1989: NonStop Cyclone is introduced for high-end mainframe workloads, alongside the Integrity line of Unix-based servers. 

Architecture Transitions (1990s–2000s)

• 1991: Cyclone/R (CLX/R) marks the start of the TNS/R migration to MIPS microprocessors.
• 1993: NonStop Himalaya K-series is released, featuring native-mode Guardian OS on MIPS R4400 processors.
• 1994: Open System Services (OSS) adds a POSIX-compliant environment to the NonStop Kernel.
• 1997: NonStop Himalaya S-Series introduces ServerNet, replacing older bus technologies with high-speed point-to-point connections.
• 1997: Compaq acquires Tandem Computers to bolster its high-end enterprise server offerings.
• 2002: Hewlett-Packard (HP) acquires Compaq, bringing Tandem technology under the HP banner as the NonStop Enterprise Division.
• 2005: The HP Integrity NonStop (TNS/E) series is launched, migrating the architecture from MIPS to Intel Itanium processors. 

The Modern Era (2010s–Present)

• 2014: NonStop X (TNS/X) is introduced, transitioning the platform to standard Intel x86-64 processors.
• 2015: HP splits into HP Inc. and Hewlett Packard Enterprise (HPE); the NonStop line moves to HPE.
• 2017: Virtualized NonStop (vNS) is introduced, allowing the system to run in software-defined data centres and cloud environments.
• 2020: HP ends sales of Itanium-based systems in July, completing the transition to the x86 platform.
• 2024: The NonStop community celebrates 50 years of Tandem/NonStop technology.