Green Hills Software, founded in 1982, develops real-time operating systems (RTOS), embedded development tools, optimizing compilers, and hypervisors for safety-critical and security-critical embedded systems. The company serves markets including aerospace and defense, automotive, industrial, medical, consumer electronics, and networking/telecom. Their core product line centers on the INTEGRITY RTOS family, which includes INTEGRITY, INTEGRITY-178 tuMP (certified to EAL 6+ and DO-178B/C), and µ-velOSity RTOS. Virtualization products include the INTEGRITY Multivisor and µ-visor Hypervisor. Development tools include the MULTI IDE, AdaMULTI IDE, optimizing compilers, the TimeMachine Debugger, and the DoubleCheck static analyzer. Hardware debug products include processor probes such as the SuperTrace Probe and Green Hills Probe V4. OS middleware covers networking, file systems, and USB stacks. The company's software supports multiple processor architectures including Arm, Power Architecture, Intel, RH850, RISC-V, and AURIX/TriCore. Their INTEGRITY RTOS has been deployed in high-assurance programs such as the F-35 fighter jet avionics and certified helicopter engine controls (FADECs). Green Hills Software also offers professional services including training, consulting, performance tuning, and production customization. Their security-focused RTOS products are designed to enforce separation between software components, supporting mixed-criticality system architectures commonly required in aerospace, defense, and automotive safety applications.