RTOS of choice for
Embedded Developers


Discover PX5 RTOS
Enhance Simplify Unite


Discover one of the most advanced, smallest, fastest, certified safe, and secure real-time operating systems (RTOS). With broad processor and tool support as well as a native implementation of the industry-standard POSIX pthreads API, PX5 RTOS enhances your embedded software development, enables cross-platform application sharing, and helps protect your investment.


Install PX5 RTOS in three easy steps—only minutes of your time! Designed for simplicity and offering a native implementation of the POSIX pthreads API, only minimal learning is needed before you start building your embedded RTOS application.


Embedded Linux is the most popular embedded RTOS platform. But it’s not the best embedded RTOS—that’s PX5 RTOS. Embedded Linux is too memory and processing-intensive for resource-constrained and hard real-time embedded applications. PX5 RTOS delivers the same API as in embedded Linux to resource-constrained devices, uniting the embedded RTOS industry through the standard POSIX pthreads API.

pthreads United

Linux &
Embedded Linux

Industrial Grade RTOS

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

Ultrahigh Performance

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

Ultrasmall Size

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

Safe and Secure

Designed for safety and security with patent-pending pointer/data verification (PDV) technology and extensive testing (100% statement and branch decision coverage), PX5 is a certified-safe and secure RTOS.

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

Simple To Use

Install and use this RTOS in minutes. With a native implementation of the POSIX pthreads standard, your team can focus immediately on developing your application—no proprietary RTOS API to learn.

An RTOS Built for developers

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


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


Fast & Efficient

This RTOS 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.

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

Safety-certified RTOS

SGS-TUV Saar pre-certifies that PX5 RTOS complies with IEC-61508 SIL 4 (electronic), IEC 62304 Class C (medical), ISO 26262 ASIL D (automotive), and EN 50128 (rail) functional safety standards. PX5 RTOS is suitable for developing safety-critical software to the highest integrity levels (SIL 4). Learn more about our RTOS.

Safety Certified PX5 RTOS
Certified Safest PX5 RTOS

You Are
Not Alone!

We deliver professional, fully ticketed and tracked support to you.

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

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You Benefit

PX5 RTOS provides technical benefits that create business advantages for you:

  • Faster time-to-market
  • Enhanced product quality
  • Safer and more secure products
  • Easier functional safety certification
  • PX5 RTOS provides technical benefits that create business advantages for you
  • Cross-platform application support
  • Reduced engineering training via pthreads API
  • Professional support
PX5 RTOS Benefits


PX5 RTOS enables higher-quality IoT devices faster—even for the most demanding applications:

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

Press Release
May 21, 2024

PX5 Brings Advanced Storage Solutions to Embedded Systems

PX5 FILE couples the unparalleled interoperability of the FAT file format and Linux file system API to address storage needs of resource-constrained, real-time embedded systems

Trusted & Proven

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