18.6
OPNsense is an open-source firewall and routing platform based on FreeBSD, for self-hosted, web, and API use.
Free planOpen sourceAndroidiOSWeb
Best Operating Systems in 2026
Operating systems form the software base for devices and workloads, from servers to other supported device types. Compare app compatibility, CPU architectures and deployment models to see how each option may fit your environment; built-in management and support lifecycle add operational context. Free-plan availability and paid-from pricing help round out the comparison. The named entries include pfSense, AlmaLinux…
27.8
OpenWrt is a Linux operating system for embedded devices, most often wireless routers.
Free planOpen sourceAndroidWebAPI
37.6
Kali Linux is a Debian-based distribution for advanced penetration testing and security auditing.
Free planOpen sourceAndroidLinuxmacOS
- 4
Apache NuttX
Apache NuttX is a free real-time operating system for embedded systems, designed around standards compliance and a small footprint.
Free planOpen sourceAPILinuxmacOSSelf-hosted7.3Free plan - 5
AlmaLinux OS
AlmaLinux OS is a free, open-source, community-owned enterprise Linux distribution that is binary compatible with RHEL.
Free planOpen sourceAPILinuxSelf-hostedWindows7.1Free plan - 6
pfSense
pfSense is a free, open-source firewall and router distribution based on FreeBSD, managed through a web interface.
Free planWebLinuxSelf-hosted7.0Free plan - 7
Manjaro Linux
Manjaro Linux is a free Linux distribution based on Arch Linux, designed to make Arch’s power and flexibility more accessible.
Free planOpen sourceLinuxSelf-hosted6.9Free plan - 8
Pop!_OS
Pop!_OS is a free Linux operating system from System76 for productive, customizable computer use.
Free planOpen sourceLinux6.9Free plan - 9
Nix
Nix is a package manager and system configuration tool for creating reproducible, declarative environments.
Free planLinuxmacOSSelf-hostedWindows6.7Free plan - 10
Ubuntu Server
Ubuntu Server is a Linux server operating system for enterprise data centers, public and private clouds, Kubernetes clusters and render farms.
Free planLinuxSelf-hosted6.6From $25 a year - 11
OmniOS
OmniOS is an open-source server operating system based on illumos for physical servers and virtual machines.
Free planLinuxSelf-hosted6.5From $500 a year - 12
postmarketOS
postmarketOS, now called Nura, is a free, open-source operating system project focused on extending the life of consumer electronics.
Free planAndroidLinux6.5Free plan - 13
MX Linux
MX Linux is a free family of Linux operating systems built from Debian Stable repositories for efficient desktop use, stability and performance.
Free planLinux6.3Free plan - 14
Solus
Solus is a free, independent Linux operating system for personal computers, including desktops and laptops with 64-bit x86-64 processors.
Free planLinux6.3Free plan - 15
ChromeOS
WebLinux6.2 - 16
Raspberry Pi Imager
Raspberry Pi Imager is a free utility for writing Raspberry Pi OS and other operating systems to storage media for use with a Raspberry Pi.
Free planLinuxmacOSWindows6.2Free plan - 17
Rocky Linux
Rocky Linux is a free, open-source enterprise operating system designed for bug-for-bug compatibility with Red Hat Enterprise Linux.
Free planLinuxSelf-hostedWindows6.1Free plan - 18
Amazon Linux
Amazon Linux is a free Linux distribution for EC2 instances and Docker container workloads.
Free planLinuxSelf-hosted6.0Free plan - 19
FreeRTOS
FreeRTOS is a real-time operating system for microcontrollers and small microprocessors.
Free planLinuxWindows6.0Free plan - 20
Photon OS
Photon OS is a free, open-source Linux appliance operating system built for cloud and edge applications.
Free planLinuxSelf-hosted6.0Free plan - 21
Sailfish OS
AndroidLinux6.0From €4.90 a month - 22
Ubuntu Touch
Free planAndroidSelf-hosted6.0Free plan - 23
Alpine Linux
Alpine Linux is a free, independent Linux distribution for power users who value security, simplicity, and efficient resource use.
Free planLinuxSelf-hosted5.9Free plan - 24
Debian
Debian is a free operating system created by the Debian Project, an association of individuals.
Free planLinuxSelf-hosted5.9Free plan - 25
OpenIndiana
OpenIndiana is a free, community-developed, illumos-based Unix-like operating system derived from OpenSolaris.
Free planLinuxSelf-hosted5.9Free plan