Best Free Network Operating Systems (NOS) of 2025

CacheGuard product line is based on a core product called CacheGuard-OS. Once installed on a bare metal or virtual machine, CacheGuard-OS transforms that machine into a powerful network appliance . The resulted appliance can then be implemented as different types of Gateways to Secure & Optimize your network. See below a brief description of all CacheGuard appliances. - Web Gateway: gain control over the Web traffic in your organization & filter unwanted Web traffic in your organization. - UTM (Unified Threat Management) : secure your networks against all kind of threats coming from the internet with a Firewall, an Antivirus at the Gateway, a VPN server and a Filtering proxy. - WAF (Web Application Firewall): block malicious requests on your critical Web applications and protect your business. The WAF integrates OWASP rules with the possibility to design your own custom rules. In addition, an IP reputation based filtering allows you to block IPs listed in real time blacklists. - WAN Optimizer : prioritize your critical network traffic, save your precious bandwidth and get High Availability for your internet access through multiple ISP.

Open source software and a universal router are key to democratizing the way we access networks. VyOS' vision is to revolutionize how we access networks, so that everyone can build the solutions they have always wanted, without limitations, restrictions, or prohibitive prices. We believe that internet access is just as important to human development as food, water, air, and healthcare. VyOS was founded by engineers for engineers. It is an open-source software company that makes it possible to access networks without restrictions or prohibitive fees. Through our open-source software and virtual platforms, we do this as VyOS. Stateful firewalls, zone based firewall, all types source and destination NAT (one-to-one, one-to many, many to many). For auditing, creating customized images and contributing, everyone has access to the entire codebase and build toolchain.

FreeBSD stands out with its sophisticated networking, exceptional performance, security, and compatibility elements that many other operating systems, including several top commercial options, still lack. It serves as a prime choice for both Internet and Intranet servers, delivering reliable network services even under extreme loads while efficiently managing memory to ensure excellent response times for numerous simultaneous user processes. Moreover, FreeBSD extends its advanced operating system capabilities to both appliance and embedded systems, accommodating a diverse range of hardware platforms such as higher-end Intel-based devices, as well as ARM, PowerPC, and MIPS architectures. Vendors globally depend on FreeBSD for their embedded products, which encompass everything from mail and web appliances to routers, time servers, and wireless access points, thanks to its integrated build and cross-build environments. Additionally, the Berkeley open-source license allows these vendors the flexibility to determine the extent of their contributions back to the community, fostering collaboration and innovation. This combination of features makes FreeBSD an invaluable asset for developers aiming to create high-performance embedded solutions.