Discover PX5 RTOS
Enhance Simplify Unite


The advanced PX5 RTOS is one of the smallest, fastest, certified safest, and most secure real-time operating systems on the market today. With broad processor/tool support and a native implementation of the industry-standard POSIX pthreads API, the PX5 RTOS enhances development, enables cross-platform application sharing, and helps protect your software investment.


The PX5 RTOS is designed for simplicity. It can be installed in three easy steps—taking only minutes of your time! Since PX5 RTOS offers a native implementation of the well-known POSIX pthreads API, minimal learning is required before you can start building your application.


Embedded Linux is one of the most popular embedded OS platforms, accounting for as much as 70% of the embedded market. However, it is too memory and processing-intensive for resource-constrained or hard real-time embedded applications. The PX5 RTOS real-time operating system brings the same API found in embedded Linux to resource-constrained devices, uniting the embedded RTOS industry around the industry-standard POSIX pthreads API!

pthreads United

Linux &
Embedded Linux

Industrial Grade

PX5 RTOS is an advanced, 5th generation real-time operating system designed for the most demanding embedded applications.

Ultrahigh Performance

Its ultrahigh performance (sub-microsecond context switching and API calls on most microprocessors) and rich determinism make it ideal for the most demanding real-time needs.

Ultrasmall Size

Its ultrasmall size (< 1KB for minimal use) allows the PX5 RTOS to fit into some of the most memory-constrained devices.

Safe and Secure

The PX5 RTOS is designed explicitly for safety and security, including its patent-pending Pointer/Data Verification (PDV) technology and extensive testing (100% statement and branch decision coverage).

In addition, the PX5 RTOS is certified to the highest levels of the IEC 61508 functional safety standard, specifically IEC 61508 SIL 4, IEC 62304 Class C, ISO 26262 ASIL D, and EN 50128 SW-SIL 4.

Simple To Use

You can install and use the PX5 RTOS in minutes. With a native implementation of the POSIX pthreads industry standard, your team can immediately focus on your application - no learning of a proprietary RTOS API is required!

Built for developers

Built for simplicity, the PX5 real-time operating system consists of just two source files: px5.c and px5_binding.s. Installing and using the PX5 RTOS takes just three steps that can be done in minutes!


Place the PX5 RTOS distribution (px5.c, px5_binding.s and header files) into your C main project source directory.


Add px5.c and px5_binding.s to your project (IDE or makefile)—no complicated project or linker control file changes are necessary.


Modify your C main program to include pthread.h and call px5_pthread_start in your main program. The PX5 RTOS upconverts your main program to your first thread. You are now ready to use the PX5 RTOS.


Fast & Efficient

The PX5 real-time operating system is extremely fast and efficient. On typical 32-bit microcontrollers running at 80MHz, most API calls and context switches complete in less than one microsecond.

The PX5 RTOS is also deterministic. The processing for each API and context switch is completely predictable and unaffected by the number of active threads.

Functional Safety Certification

The PX5 RTOS has earned certification from SGS-TUV Saar for safety-critical systems. Complying with IEC-61508 SIL 4, IEC-62304 Class C, ISO 26262 ASIL D, and EN 50128 standards, it is deemed suitable for developing safety-related software at the highest integrity levels. SGS-TUV Saar, a collaboration between Germany’s SGS-Group and TUV Saarland, is a premier independent entity for testing and certifying embedded software globally. Standards like IEC 61508, IEC-62304, ISO 26262, and EN 50128 ensure functional safety across diverse sectors such as medical devices, industrial machinery, automobiles, and railway control systems.

Safety Certified PX5 RTOS
Certified Safest PX5 RTOS

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We deliver professional, fully ticketed and tracked support.

The PX5 RTOS enhances, simplifies and unites embedded development. Our professional support helps us deliver on this promise!

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You Benefit

The PX5 real-time operating system provides many technical benefits that create business advantages, including:

  • Faster time-to-market
  • Enhanced product quality
  • Safer and more secure products
  • Easier functional safety certification
  • More portable/reusable application code via the industry-standard pthreads API
  • Cross-platform application support
  • Reduced engineering training via pthreads API
  • Professional support
PX5 RTOS Benefits


The PX5 real-time operating system enables higher-quality IoT devices in record time—even for the most demanding applications—including:

  • System-on-Chip (SoC)
  • Industrial
  • Medical devices
  • Consumer electronics
  • Automotive
  • Office automation
  • Networking
  • Military/Aerospace

Press Release
April 4, 2024

PX5 Announces Functional Safety Certification of the PX5 RTOS

PX5 Announces Functional Safety Certification of the PX5 RTOS, Offering Developers a Faster Path to Certification, Reducing Product Liability, Improving Quality and Time to Market

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