The evolution of C++ on HPE NonStop systems traces the platform’s transition from proprietary Tandem architectures to modern x86-64 standards.

HPE NonStop C++ Evolution Timeline

• Early 1990s: Introduction of Native C/C++ (TNS/R)
  With the move to MIPS-based TNS/R architecture, Tandem introduced native C and C++ compilers. These supported the Guardian and the then-new Open System Services (OSS) personalities.
• 2005: Itanium Transition (TNS/E)
  As the platform migrated to Intel Itanium processors (J-Series), the C++ compiler was updated to support the TNS/E (Tandem Native Stack / EPOC) architecture. This era introduced more robust Standard C++ Library support, though it required specific header management (e.g., CPATHEQ pragmas).
• 2015: x86 Migration (TNS/X)
  The launch of NonStop X (L-Series) on Intel x86-64 marked a major shift. The compiler suite was re-engineered to leverage the x86-64 Instruction Set Architecture, providing significantly higher performance for C++ applications.
• 2017: 64-Bit Addressing Support
  HPE introduced comprehensive 64-bit support for OSS processes (LP64 data model). This allowed C++ applications to access massive memory heaps beyond the previous 32-bit (ILP32) limits.
• 2020–2022: Modern C++ Standards (C++11/14/17)
  HPE updated its toolchains to support modern language standards. The NonStop Development Environment for Eclipse (NSDEE) 13.x versions specifically introduced a dedicated UI for setting the C++17 Language Standard.
• 2024: Kernel-Level Threading (KLT)
  The release of the L25.09 RVU brought Kernel-Level Threading to native C++ applications. This allowed C++ threads to execute concurrently across different IPUs, moving beyond the older POSIX User Threads (PUT) model.
• 2025: Cloud-Native Development
  HPE now offers the HPE NonStop Development Environment (NSDevEnv) in the public cloud, allowing developers to build fault-tolerant C++ applications using a cross-compiler model without on-premise hardware. 

Evolution of C++ on HPE NonStop Tandem systems