Best Real-Time Operating Systems (RTOS)

Developed in partnership with the world’s leading chip companies over a 15-year period, and now downloaded every 170 seconds, FreeRTOS is a market-leading real-time operating system (RTOS) for microcontrollers and small microprocessors. Distributed freely under the MIT open source license, FreeRTOS includes a kernel and a growing set of IoT libraries suitable for use across all industry sectors. FreeRTOS is built with an emphasis on reliability and ease of use. With proven robustness, tiny footprint, and wide device support, the FreeRTOS kernel is trusted by world-leading companies as the de facto standard for microcontrollers and small microprocessors. With detailed pre-configured demos and Internet of Things (IoT) reference integrations, there is no need to determine how to setup a project. Quickly download, compile, and get to market faster. Our partner ecosystem provides a breadth of options including community contributions and professional support.

Arm Mbed OS is a free, open-source IoT operating system that includes all the necessary features to develop IoT products. The OS includes everything you need to develop smart, connected products on Arm Cortex-M based hardware, including machine learning capabilities, security, connectivity stacks, an RTOS kernel and drivers for sensors and I/O devices. Arm Mbed OS is designed for the Internet of Things. It is integrated with connectivity, machine learning, networking, and security stacks and is supported with software libraries, development hardware, tutorials and examples. From hardware to the cloud, Mbed OS supports more than 70 silicon, module, cloud, and OEM partners, optimizing your developer choice. By using the Mbed OS API, your application code can remain clean, portable, and simple, while taking advantage of security, communications and machine learning. The integrated solution reduces development cost, time, and risk.

embOS is a priority-controlled RTOS (real-time operating system). It is designed to be the foundation for developing embedded applications and is continually developed since 1992. embOS is available for all popular cores, compilers and development tools and has been deployed in several billion devices in a range of application areas. Since 1992, embOS has been the preferred RTOS choice for engineers in the embedded market. It offers ease-of-use and guarantees 100% deterministic real-time operation for any embedded device. This real-time operating system is highly portable and fully source-compatible on all platforms, making it easy to port applications to different cores. Tasks can easily be created and safely communicate with each other, using communication mechanisms such as semaphores, mailboxes, and events. The real-time operating system is free for any non-commercial use like education and evaluation, without any technical limitation.

The SCIOPTA architecture is specifically designed to provide excellent real-time performance and small size. Internal data structures, memory management, interprocess communication and time management are highly optimized. SCIOPTA is a pre-emptive real-time kernel. Interrupts can be serviced at any time, even inside the kernel. SCIOPTA is a message based real-time operating system. A powerful set of system calls is available to control the resources. Standardized processes and interprocess communication result in clear system designs and are easy to write, to read and to maintain. As processes are communicating with well defined messages and processes can be grouped into modules, SCIOPTA systems are very well suited for team work in big projects. The time-to-market will be reduced dramatically. SCIOPTA is designed on a message based architecture allowing direct message passing between processes. Messages are mainly used for interprocess communication and synchronization.

Since 1980, thousands of companies have deployed QNX’s real-time operating systems to ensure the ideal combination of performance, security and reliability in mission-critical systems. At the core of QNX technology is the QNX Neutrino® Real-time Operating System (RTOS), a full-featured RTOS enabling next-generation products in every industry where reliability matters, including automotive, medical devices, robotics, transportation, and industrial embedded systems. With the QNX microkernel architecture, a component failure doesn’t bring down other components or the kernel. The failed component is simply shut down and restarted without adversely affecting the rest of the system. The QNX Neutrino RTOS offers the determinism only a real-time OS can provide. Techniques such as adaptive partitioning guarantee critical processes get the cycles they need to complete their tasks on time, while maintaining the performance your complex embedded systems require.

The MQX real-time operating system (RTOS) provides real-time performance within a small, configurable footprint. The RTOS is tightly integrated with 32-bit MCUs and MPUs from NXP and is provided with commonly used device drivers. The MQX RTOS is designed to have a modern, component-based microkernel architecture allowing for customization by feature, size, and speed by selecting the components engineers wish to include while meeting the tight memory constraints of embedded systems. The MQX RTOS can be configured to take as little as 8 KB of ROM and 2.5K RAM on Arm Cortex M4, including kernel, 2 task applications,1 LW Semaphore, interrupt stack, queues, and memory manager. Provides a fully-functional RTOS core with additional, optional services. Components are linked in only if needed, preventing unused functions from bloating the memory footprint. Key components are included in both full and lightweight versions for further control of size, RAM/ROM utilization and performance options.

Tizen is an open and flexible operating system built from the ground up to address the needs of all stakeholders of the mobile and connected device ecosystem, including device manufacturers, mobile operators, application developers and independent software vendors (ISVs). Tizen platform is commercialized on smart TVs, smartphones, wearable devices (Gear S, Gear Fit), and smart home appliances. However, low-end and low-cost IoT devices, such as home appliances without display and wearable bands with a small LCD, have received less attention. The objective of TizenRT is to extend the Tizen platform device coverage to these kind of low-end devices.

Huawei LiteOS is an IoT-oriented software platform integrating an IoT operating system and middleware. It is lightweight, with a kernel size of under 10 KB, and consumes very little power — it can run on an AA battery for up to five years! It also allows for fast startup and connectivity and is very secure. These capabilities make Huawei LiteOS a simple yet powerful one-stop software platform for developers, lowering barriers to entry for development and shortening time to market. Huawei LiteOS provides a unified open-source API that can be used in IoT domains as diverse as smart homes, wearables, Internet of Vehicles (IoV), and intelligent manufacturing. Huawei LiteOS enables an open IoT ecosystem, helping partners to quickly develop IoT products and accelerate IoT development.

The µ-velOSity RTOS is the smallest of Green Hills Software's family of real-time operating systems. Implemented as a C library, it can be easily ported to a number of target architectures. It has a streamlined design and is tightly integrated with the MULTI IDE, making µ-velOSity both easy-to-learn and simple-to-use. µ-velOSity offers a clear, concise API that reduces development time and improves product maintainability. As a result, you can cut costs and speed time-to-market. For developers moving from standalone or no-OS configurations. With its efficient design and minimal footprint, µ-velOSity fits better in on-chip memory than competing products. Eliminating the need to access off-chip memory dramatically increases execution speed. µ-velOSity was designed to minimize the number of CPU clock cycles needed to boot, which is critical in embedded devices that require extremely fast boot times. µ-velOSity is also the ideal RTOS for embedded devices with stringent power requirements.

TI-RTOS accelerates development schedules by eliminating the need to create basic system software functions from scratch. TI-RTOS scales from a real-time multitasking kernel - TI-RTOS Kernel - to a complete RTOS solution including additional middleware components, device drivers and power management. TI-RTOS and TI's ultra low-power MCUs combine to enable developers to design applications with much longer battery life. By providing essential system software components pre-tested and pre-integrated, TI-RTOS enables developers to focus on differentiating their application. TI-RTOS builds on existing proven software components to ensure reliability and quality. It augments these with documentation, additional examples and APIs appropriate for multitasking development and integration testing to verify that all components work together.

Azure RTOS is an embedded development suite including a small but powerful operating system that provides reliable, ultra-fast performance for resource-constrained devices. It’s easy-to-use and market-proven, having been deployed on more than 10 billion devices worldwide. Azure RTOS supports the most popular 32-bit microcontrollers and embedded development tools, so you can make the most of your team’s existing skills. Easily connect to cloud and local networks, develop durable flash file systems, and design elegant user interfaces. Code that has been certified to meet stringent industry safety and security standards. Clean, clear code is easier to use and maintain and can lower total cost of ownership. Most safety-related certifications require you to submit the complete source code for your software, including the RTOS.

PikeOS offers a separation kernel-based hypervisor with multiple partitions for many other operating systems and applications. It enables you to build smart devices for the Internet-of-Things (IoT) according to the quality, Safety and Security standards of your industry. Due to its separation kernel approach, PikeOS is the first choice for systems which demand protection against Cyber-Security attacks. In addition to the broad usage within millions of IoT and edge systems, it has also been deployed within various high critical communication infrastructures. PikeOS brings together virtualization and real-time by means of unique and never seen before technologies. It allows you to migrate numerous complex embedded circuit boards in to a single hardware. It does not stop when it comes to new hardware concepts such as Big-SoCs with multiple heterogeneous processor cores. PikeOS runs on several architectures, supporting processors that come with a memory management unit (MMU).

From simple embedded environmental sensors and LED wearables to sophisticated embedded controllers, smart watches, and IoT wireless applications. Implements configurable architecture-specific stack-overflow protection, kernel object and device driver permission tracking, and thread isolation with thread-level memory protection on x86, ARC, and ARM architectures, userspace, and memory domains. For platforms without MMU/MPU and memory constrained devices, supports combining application-specific code with a custom kernel to create a monolithic image that gets loaded and executed on a system’s hardware. Both the application code and kernel code execute in a single shared address space.

NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 32-bit microcontroller environments, the primary governing standards in NuttX are Posix and ANSI standards. Additional standard APIs from Unix and other common RTOS’s (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()). Apache NuttX is an effort undergoing Incubation at The Apache Software Foundation (ASF), sponsored by the Incubator. Incubation is required of all newly accepted projects until a further review indicates that the infrastructure, communications, and decision making process have stabilized in a manner consistent with other successful ASF projects.