List of the Top 25 On-Prem Operating Systems in 2025

TrueNAS stands out as the most widely used storage software globally. It serves as a comprehensive data platform that enables users to seamlessly embrace a contemporary, open-source method for both storing and safeguarding their expanding data needs. Leveraging the formidable ZFS file system, TrueNAS is open source and delivers unified storage solutions across various formats (File, Block, Object, and Apps), ensuring the reliability and performance essential for virtualization, backup operations, and numerous other data-intensive applications. This flexibility makes it an ideal choice for organizations looking to enhance their data management capabilities.

OpenIndiana is an operating system tailored for the illumos community, emerging from the UNIX lineage, which may initially seem intricate. Nevertheless, with some foundational knowledge and assistance, you'll find that it provides some of the most intuitive tools available to users. Similar to other UNIX-like systems, it can be completely controlled via a Command Line Interface (CLI) shell, while also offering a graphical user interface (GUI) option. The CLI is equipped with multiple shells, primarily ksh93 and Bash, and it maintains compatibility with the traditional SunOS SVR4 commands, as well as the command syntax that BSD users are accustomed to, in addition to a substantial array of GNU userland commands favored by Linux enthusiasts. This versatility empowers users to select from a diverse set of commands within their shell setups, fostering an environment tailored to their individual preferences. As a result, OpenIndiana is distinguished by its adaptability, making it approachable for a broad spectrum of users, from beginners to expert practitioners, and it continues to evolve with the needs of its community.

Windows Server 2022 introduces advanced security measures, hybrid capabilities with Azure, and a flexible platform for applications. It is essential to strengthen your organization's security protocols at the operating system level. By integrating your data center with Azure, you can enhance IT operational efficiency significantly. Developers and IT teams benefit from a comprehensive application platform that supports the creation and deployment of diverse applications. Utilizing Azure can lead to considerable savings, thanks to advantages such as the Azure hybrid benefit and extended security updates. Azure is celebrated as a dependable cloud solution for Windows Server, enabling you to transform your workloads seamlessly. Connecting your on-premises Windows Servers to Azure is effortless through Azure Arc. Transitioning to this latest operating system allows you to experience improved security, performance, and overall value. With Azure, you can fully leverage the extensive benefits of cloud computing. Initiating this process is free, making it easier to manage servers, clusters, hyper-converged infrastructure, and Windows 10 PCs effectively. This approach ensures that your shift to cloud services is not only smoother but also remarkably efficient in today's digital landscape. Additionally, you can take advantage of ongoing support and updates to stay ahead in technology advancements.

NomadBSD is a persistent live operating system tailored for USB flash drives and is based on FreeBSD®. It boasts automatic hardware detection and configuration, allowing for instant deployment as a desktop system, while also being useful for tasks like data recovery, educational purposes, or assessing hardware compatibility with FreeBSD®. The images, which can accommodate both 64-bit and 32-bit architectures, require a minimum of 5GB on a USB flash drive, and a system with at least a 1.2GHz CPU and 1GB of RAM is sufficient to run NomadBSD effectively. Users can initiate the system through either BIOS or UEFI methods. A new versioning system has recently been implemented, following the format FFfX-YYYYMMDD, where FF denotes the major two-digit version of FreeBSD, 'f' signifies the minor version, and 'X' indicates the status as ALPHA (A), BETA (B), RC, or RELEASE (R), succeeded by the release date. This modernized versioning system enhances the distribution of images containing different FreeBSD versions, thereby improving the system's versatility and user-friendliness. Furthermore, it allows users to choose the version that best aligns with their specific requirements, fostering a more customized experience. The flexibility in version selection empowers users to tailor their NomadBSD experience to their individual needs and preferences.

NetBSD is an entirely free, swift, secure, and remarkably versatile open-source operating system that resembles Unix. It supports a wide range of platforms, including powerful servers, efficient desktop systems, and portable devices. Since its inception in 1993, NetBSD's code has infiltrated many unexpected environments, largely owing to its established reputation for quality, cleanliness, and dependability. It is fundamentally based on 4.4BSD Lite2, which was developed at the University of California, Berkeley. Rather than being a conventional "distribution," NetBSD has evolved over the decades into a unique and all-encompassing operating system within the BSD family, bolstered by a worldwide community of developers. Users enjoy a seamless, well-documented UNIX-like experience characterized by simplicity while also incorporating a plethora of modern features and ensuring compatibility with the latest hardware. This blend of characteristics has established NetBSD as an attractive option for both tech enthusiasts and industry professionals. As it continues to grow, its community remains dedicated to enhancing its capabilities and preserving its core values.

The OpenBSD operating system is entirely crafted by a dedicated group of volunteers. The development environment and various events for developers receive funding through donations that are overseen by The OpenBSD Foundation. These contributions are essential for maintaining the availability and sustainability of OpenBSD as a free operating system. Consequently, the OpenBSD project has implemented cryptographic capabilities across numerous aspects of the system. We emphasize that any cryptographic software used must be free of charge and possess suitable licenses. We deliberately avoid using cryptography that is burdened by problematic patents. Furthermore, we focus on obtaining this software from nations with favorable export laws, as we are dedicated to complying with international regulations. Our decision-making is primarily driven by technical merit, steering clear of political considerations wherever feasible. This unwavering commitment to free software and adherence to legal standards highlights the integrity and principles of the OpenBSD project. The ongoing efforts of the community continue to shape OpenBSD into a secure and reliable operating system for users worldwide.

Unraid OS offers exceptional capabilities for managing data, media, applications, and desktops, allowing users to utilize almost any hardware setup. It's especially advantageous for video creators, streamers with extensive video libraries, media editors, photographers, musicians, and music lovers aiming to reduce initial costs. With the ability to start with just two drives, users can gradually expand their storage as their needs grow. Gamers who also run media servers and prefer to tailor their systems depend on Unraid to ensure top-tier performance without sacrificing efficiency. Additionally, professionals such as designers, 3D animators, developers, and photographers use Unraid to store substantial amounts of assets locally, providing swift and effective access. You can also utilize backup services like Apple Time Machine and Windows Backup to securely preserve large datasets that are not accessed regularly. Moreover, software engineers, game development studios, AR/VR designers, and educational facilities benefit from Unraid by testing across multiple platforms and operating systems, which streamlines their workflows and boosts productivity. This adaptability and comprehensive functionality make Unraid an indispensable resource for anyone eager to enhance their data management strategies, regardless of their field or requirements. Ultimately, Unraid’s unique features empower users to tailor their storage solutions to their specific needs.

OS108 is a fast, clear, and secure desktop operating system built upon the NetBSD framework. The name has an interesting origin, as it relates to the fact that a byte is made up of binary bits grouped as 1s and 0s in sets of eight, while also referencing the distance between the Earth and the Sun, which is about 108 times the diameter of the Sun. We are always on the lookout for contributors who want to be actively involved in the project in various ways. Even if you don't have programming skills, there are many ways you can contribute, such as writing how-to guides, crafting user-friendly documentation, or engaging in support forums to help other users. Your participation can greatly enrich the community and enhance the overall experience for all members. Everyone's contribution, no matter the skill level, is valuable and helps foster a collaborative environment.

It includes all the vital software you need for daily tasks, such as managing email, browsing the web, editing documents, playing games, and a wide range of other applications. MidnightBSD, developed by a dedicated but small team of enthusiasts, strives to create an easily accessible operating system that anyone can utilize without charge. This operating system is designed to work with x86 and AMD64 architectures and can also be operated as a virtual machine. Although the FreeBSD project has created a powerful server operating system, it often overlooks the usability and performance features essential for desktop environments. Customizing aspects like scheduling, resource distribution, security protocols, and application support is essential for adequately addressing the needs of desktop users. Many BSD-based initiatives primarily focus on server functionality or legacy systems, and while some versions of FreeBSD provide a more user-friendly graphical interface, they still retain a server-centric architecture. Our choice to fork FreeBSD stemmed not from disagreements but from recognizing it as an outstanding platform to enhance. Ultimately, our mission is to harmonize the efficiency of server systems with the needs of desktop users, creating a seamless experience for all. By doing so, we hope to attract a wider audience and foster a community around this innovative operating system.

OmniOS is a server operating system that is open-source and focuses on incorporating only the most necessary features. Featuring ZFS as its native file system, it combines a volume manager with advanced data protection mechanisms that ensure integrity. Users can easily share storage volumes through various protocols, including iSCSI, CIFS, and NFS. Moreover, OmniOS provides the capability to run lightweight virtual machines, whether they're running OmniOS or Linux in containers, which helps eliminate the overhead typically associated with traditional hypervisors while maintaining effective resource management. For users who require comprehensive hardware virtualization, it also supports virtualization technologies such as bhyve and KVM, enabling the use of diverse guest operating systems like Microsoft Windows and FreeBSD. The network infrastructure can be efficiently virtualized using Crossbow, which facilitates the creation of virtual interfaces and switches, and offers the ability to assign dedicated resources for particular applications. DTrace acts as a sophisticated dynamic tracing framework that significantly aids troubleshooting across the entire software stack, providing real-time instrumentation as necessary. As an open-source initiative, OmniOS operates in a self-hosting manner, with its development actively overseen on GitHub; this platform allows contributors to submit pull requests while granting anyone interested the ability to access the source code to compile their own version. This collaborative environment not only promotes community engagement but also ensures a high level of transparency throughout the development process, encouraging contributions from a diverse range of developers.

The recent update of DragonFly, now at version 6.2.2, brings forth a range of improvements, such as better hardware compatibility for type-2 hypervisors that use NVMM, an enhanced amdgpu driver, and an experimental capability for remote-mounting HAMMER2 volumes, in addition to a host of other revisions. Being part of the BSD family, DragonFly traces its origins back to Linux and various BSD variants, while maintaining the core UNIX principles and APIs, yet it takes a separate path in its development from FreeBSD, NetBSD, and OpenBSD. This unique trajectory allows DragonFly to explore innovative features, including its advanced HAMMER filesystem, which is designed for high performance and includes built-in mirroring along with historical access functions. Among its impressive features is the introduction of virtual kernels, which permit the operation of a full kernel as a user process, enhancing resource management, kernel development, and debugging processes within a faster framework. The combination of these advancements makes DragonFly a compelling choice for users in search of alternatives to traditional operating systems, showcasing its commitment to pushing boundaries in the realm of system design. Furthermore, this distinctive approach positions DragonFly as a notable contender for those who prioritize innovation alongside reliability.

Enterprise-Grade Linux Tailored for Edge-to-Cloud Solutions. This joint open-source venture presents a Debian-based Linux distribution meticulously crafted for applications that operate from edge devices to cloud environments. It ensures consistent performance and stability across a variety of devices, local infrastructure, and cloud services. eLxr provides a secure and resilient distribution, drawing from the advancements made by the open-source community, and includes a reliable schedule for releases and updates that cater to long-term deployments and extended lifecycles. It is particularly well-suited for applications with stringent timing requirements, leveraging preempt-rt kernel configurations to enhance low-latency performance and guarantee that tasks are executed within precise time limits. This methodology significantly enhances determinism and predictability when juxtaposed with standard Linux kernels. eLxr has been engineered with a streamlined footprint, fostering peak performance and resource efficiency while simultaneously reducing potential security vulnerabilities. It incorporates all critical features and functionalities, ensuring efficient utilization of system resources while accommodating a wide range of deployment needs. Consequently, users can anticipate a versatile and high-performing platform that meets a variety of application demands while remaining adaptable to evolving technology landscapes.

Security Onion is a powerful open-source solution designed for intrusion detection, network security monitoring, and log management. It provides a comprehensive set of tools that allow cybersecurity professionals to detect and mitigate potential threats across an organization's network. By combining technologies like Suricata, Zeek, and the Elastic Stack, Security Onion facilitates the gathering, assessment, and real-time visualization of security-related data. Its intuitive interface makes it easy to manage and analyze network traffic, security alerts, and system logs effectively. Moreover, it includes integrated resources for threat hunting, alert triage, and forensic investigations, enabling users to quickly identify potential security breaches. Designed for scalability, Security Onion is suitable for a wide variety of settings, from small businesses to large corporations. Users also benefit from ongoing updates and strong community support, which help them to continually improve their security measures and adapt to new and emerging threats. Overall, Security Onion represents an essential tool for those looking to bolster their network defenses.

VxWorks® stands out as a premier real-time operating system, offering essential performance, reliability, safety, and security features vital for embedded computing systems in critical infrastructure. As a preemptive and deterministic RTOS, VxWorks is specifically designed to support real-time embedded applications, boasting low latency and minimal jitter. It incorporates a variety of robust security measures that effectively tackle the evolving threats faced by connected devices, ensuring protection from boot-up through operation and even during data transfer when powered off. Furthermore, VxWorks has achieved certification in stringent safety standards such as IEC 61508, ISO 26262, and DO-178C. Its architecture is not only extensible but also future-proof, enabling organizations to swiftly adapt to changing market dynamics, evolving customer needs, and technological innovations while safeguarding their investments. This adaptability ensures that VxWorks remains a relevant and valuable asset in the fast-paced world of embedded systems.

Open-source software combined with a universal router plays a crucial role in making network access more equitable for all. VyOS aims to transform the way individuals connect to networks, empowering them to create the solutions they envision without facing constraints, limitations, or exorbitant costs. We assert that access to the internet is as vital for human progress as essential resources like food, water, air, and healthcare. Founded by engineers with a passion for innovation, VyOS stands as an open-source company dedicated to facilitating unrestricted network access without financial barriers. Our mission is realized through VyOS, leveraging our open-source software and virtual platforms to provide robust solutions. We offer features such as stateful firewalls, zone-based firewalls, and various types of NAT, including one-to-one, one-to-many, and many-to-many configurations. Moreover, our commitment extends to transparency, allowing users to engage in auditing, create customized images, and contribute to the development, with full access to the entire codebase and build toolchain available to all. This collaborative approach not only enhances security but also fosters a community of innovation and shared knowledge.

IBM i is an integrated operating ecosystem developed by IBM, encompassing a comprehensive operating system, database, middleware, and an array of development tools. Tailored for creators and innovators, the latest version, IBM i 7.4, introduces continuous availability with IBM Db2 Mirror for i, enhancing user experience. This upgrade features advanced security protocols and smooth integration with emerging technologies such as IoT, AI, and Watson, ensuring that crucial applications remain operational without any downtime. The enhanced security measures comply with the most recent industry regulations, protecting essential business functions and confidential information. Additionally, a new object-level auditing feature has been implemented, alongside robust Open Source environments that support the migration of more applications to the IBM i platform. This system allows for seamless integration with IoT, AI, and Watson, thus enabling businesses to sustain productivity around the clock throughout the entire year. Users benefit from the ability to transfer virtual save media both to and from the cloud, which optimizes operational workflows. Moreover, the latest update simplifies the management of IBM i by consolidating common tasks, significantly enhancing user-friendliness and efficiency for organizations of all sizes. With these improvements, IBM i continues to evolve as a vital tool for modern businesses seeking to stay competitive in a rapidly changing technological landscape.

Discover a powerful UNIX operating system along with its tools that deliver exceptional availability, reliability, and security for mission-critical HPE Integrity servers. By utilizing this sophisticated UNIX platform, you can improve operational effectiveness while upholding the highest levels of reliability and security for your vital HPE Integrity servers. HP-UX fosters a vibrant and secure ecosystem that is seamlessly integrated with mission-critical HPE Integrity servers, allowing you to meet your specific UNIX requirements. Featuring four distinct operating environments, HP-UX is adept at addressing a variety of needs efficiently. Additionally, the system prioritizes comprehensive server security and management by incorporating HPE Systems Insight Manager, which offers essential features such as power management, health monitoring, and deployment tools. It also encompasses in-depth performance analysis tools for both kernel processes and applications, guaranteeing peak performance. Protecting your organization’s most crucial applications and services is essential for sustaining your business's positive trajectory. With these advanced capabilities, you can adeptly navigate the complexities inherent in today’s computing landscapes, ensuring you stay ahead of the competition and meet evolving challenges head-on.

GhostBSD is a desktop-oriented operating system that is user-friendly and based on FreeBSD, incorporating MATE, OpenRC, and a suite of software packages to enhance the overall experience. Users can take advantage of a range of pre-installed essential programs, allowing them to fully utilize the system right from the outset. With its GTK environment, GhostBSD provides an attractive interface and a pleasant user experience that resonates with modern BSD platforms, creating a genuine Unix work atmosphere. Its roots can be traced back to the Unix Research at the University of California, Berkeley, where it was historically known as "BSD Unix" or "Berkeley Unix," and is now often simply called BSD, which stands for Berkeley Software Distribution. The core aim of the GhostBSD project is to blend security, privacy, stability, usability, openness, and freedom, ensuring that the operating system remains free and accessible to everyone. Furthermore, the user experience is enhanced by tools like Networkmgr, which are tailored specifically for the GhostBSD environment, serving to bolster its seamless operation and user satisfaction. This dedication to ongoing enhancement and a focus on user-friendly design distinguishes GhostBSD in the competitive landscape of operating systems, making it a compelling choice for both newcomers and seasoned users alike.

Oracle Linux offers a robust and open operating system environment that integrates virtualization, management, and cloud-native computing tools, all within a single support framework. It ensures complete binary compatibility with Red Hat Enterprise Linux, which allows for smooth application execution. Additionally, you can explore a catalog that features information about independent software vendors (ISVs) that have confirmed their applications are suitable for use with Oracle Linux and its virtualization options. Applications certified on Oracle Linux are designed to operate seamlessly across multiple environments, including on-premises setups, Oracle Cloud Infrastructure, and various other cloud services. Be sure to join the Oracle Tux Tech Talk webinar on July 28, where you can learn how to benchmark performance, delve into the benefits of the Unbreakable Enterprise Kernel (UEK), and discover which workloads gain from its improvements. This informative session is set to provide you with essential knowledge for enhancing your Linux applications, making it a valuable opportunity for both new and experienced users alike. Don't miss out on the chance to advance your understanding of these powerful tools.

Illumos is an advanced Unix-based operating system that integrates state-of-the-art features beneficial for various downstream distributions, including improved system debugging, a revolutionary filesystem, sophisticated networking, and robust virtualization capabilities. It is developed through a collaborative effort involving both volunteers and companies that rely on the software for their products. As a strong platform for both conventional and cloud-native environments, illumos provides newcomers with an excellent entry point through distributions like OmniOS and OpenIndiana, which can be installed on physical machines or in virtualized environments. To compile illumos, it is essential to use an illumos-based OS, as cross-compilation is not feasible. The software is freely available via its source repository, ensuring accessibility for all. With a diverse array of technologies, illumos features capabilities like ZFS, DTrace, Zones, ctf, and FMA, among others, highlighting its versatility. We take pride in offering a stable and highly observable system that stands out due to its technological advancements. With a rich engineering heritage, illumos can trace its roots back to Sun Microsystems and the early days of UNIX and BSD, underscoring its importance in the history of operating systems. Its ongoing dedication to innovation makes it an appealing choice for both developers and users. Furthermore, illumos continues to evolve, adapting to modern computing needs while honoring its legacy.

For over two decades, we have been refining our operating system, consistently adding features that meet the evolving market needs while maintaining compatibility with legacy applications. Our Application Binary Guarantee allows users to smoothly run both modern and older applications on current infrastructures. With our sophisticated lifecycle management technologies, a single command can update your entire cloud environment, addressing everything from firmware to all virtualized areas. A significant player in the financial services industry has seen a remarkable 16-fold boost in efficiency from using Oracle Solaris for its virtual machines, surpassing a competing open-source solution. Moreover, the recent updates to the Oracle Solaris Observability tools equip users to diagnose both system and application problems in real time, supplying immediate and historical data that aids in quickly resolving issues. This suite of capabilities not only enables businesses to enhance their operational efficiency but also empowers them to adapt swiftly in a constantly changing technological environment. Ultimately, this ensures that companies are well-prepared to face future challenges and seize new opportunities.

Xinuos has unveiled UnixWare® 7.1.4, the latest iteration of its renowned UNIX® operating system. This powerful and dependable platform is crafted to support vital business applications while being budget-friendly for various computing needs. It is designed to work seamlessly with contemporary industry-standard hardware and peripherals, showcasing improved performance, scalability, and reliability—key features synonymous with the UnixWare brand. Furthermore, the default settings of the most popular versions have been fine-tuned to maximize their appeal. Users initiating new setups or upgrading to UnixWare 7.1.4 will immediately benefit from these enhancements. A new economical edition has also been launched, specifically aimed at low-cost pilot initiatives, edge computing applications, and services for smaller businesses. This advancement guarantees that even smaller enterprises can leverage state-of-the-art technology without incurring hefty expenses. With these developments, Xinuos continues to demonstrate its commitment to providing flexible and innovative solutions for businesses of all sizes.

IBM® z/OS® utilizes the powerful features of the IBM Z® platform to drive business transformation and promote innovation. It ensures a secure and stable environment crucial for optimizing performance in critical operations while equipping organizations to meet future demands. This operating system is crafted for high security and scalability, making it well-suited for vital applications. The sophisticated IBM® z16™ platform accelerates decision-making processes and protects your operations against potential threats, all while seamlessly integrating into hybrid cloud environments. With IBM z/OS V2.5, companies can tap into state-of-the-art development capabilities to enhance their hybrid cloud and AI applications, alongside sophisticated technologies concentrated on security and resilience. Moreover, a continuous delivery model guarantees that new z/OS features are rolled out quarterly without sacrificing stability, complexity, or costs, which facilitates rapid application development and deployment in hybrid cloud ecosystems. The system also provides a modernized experience that simplifies installation and management tasks, thereby boosting operational efficiency. By leveraging these advancements, organizations can adopt a transformative strategy for their IT infrastructure, ensuring they stay ahead in an ever-changing digital landscape. Furthermore, this approach enables businesses to innovate consistently while maintaining the agility required to respond to market changes.

IBM z/VM stands out as an advanced operating system that incorporates a hypervisor and virtualization capabilities, tailored to proficiently oversee guest servers, including Linux, z/OS, and z/TPF virtual machines, alongside Red Hat OpenShift on IBM Z and LinuxONE platforms. This powerful system has the capacity to run hundreds or even thousands of guest servers on a single IBM Z or LinuxONE server, showcasing exceptional efficiency and flexibility. It supports a diverse array of machine images and architectures, simplifying the migration process, facilitating application transitions, and enabling the consolidation of multiple systems into a single server environment. By optimizing resource sharing among virtual machines, IBM z/VM delivers remarkable scalability, security, and operational efficiency, ultimately leading to substantial cost savings while laying a strong groundwork for cognitive computing initiatives. Its deployment facilitates on-premises cloud computing within a hybrid cloud model, empowering organizations to effectively scale and manage extensive Linux and container workloads. Additionally, it plays a vital role in ensuring continuous availability through IBM's comprehensive resiliency solutions, which guarantee uninterrupted infrastructure for businesses. The adaptability and efficiency of IBM z/VM render it an indispensable resource for contemporary enterprises striving to enhance their IT operations and achieve greater operational agility. As the demand for robust computing solutions grows, IBM z/VM's role in the marketplace becomes increasingly critical.

For over three decades, AIX has served as the reliable platform for clients to manage their most critical applications. As we move forward into a new era, AIX is set to maintain its leadership in innovation by incorporating hybrid cloud and open-source capabilities, enabling customers to develop and deploy contemporary applications within a secure and resilient environment. It is essential for businesses to have an infrastructure that guarantees security, remarkable availability, and the adaptability necessary to meet changing market demands. AIX®️ on Power Systems not only delivers these vital attributes but also provides the performance, reliability, and security crucial for handling mission-critical data. By adopting an architecture that complements your on-premises configuration, you can optimize and accelerate the cloud deployment of your AIX applications. Additionally, you can experience zero downtime during scheduled maintenance while consistently updating AIX with the latest features and enhancements. The AIX UNIX operating system is dedicated to upholding its strong reputation for security, built over many years, ensuring that your data is safeguarded and your operations run smoothly without interruption. Moreover, AIX’s commitment to innovation guarantees its ongoing relevance in the rapidly changing technological environment, allowing organizations to thrive as they adapt to new challenges. This adaptability is vital as businesses strive to leverage technology for competitive advantage.