List of the Top 1 Network Operating Systems (NOS) for Mac in 2026

CacheGuard is a free, open-source network security gateway designed for small and medium businesses that need professional-grade internet protection without the cost of a dedicated IT team or a commercial appliance subscription. Most SMBs rely on the router their internet provider gave them. That router was built to connect, not to protect — it forwards all traffic without inspecting it, leaving the network exposed to malware, phishing, data leaks, and unauthorised access. CacheGuard fixes this by sitting between the internal network and the ISP router, acting as the security checkpoint for all internet traffic. What CacheGuard covers: Stateful firewall — control what enters and leaves your network Web antivirus — real-time scanning of HTTP/HTTPS traffic URL filtering — block websites by category or custom list SSL inspection — inspect encrypted HTTPS traffic Web Application Firewall — block malicious web requests VPN server — secure remote access for your team Web cache — faster browsing, lower bandwidth usage QoS and WAN load balancing — traffic shaping across internet links Key advantages over commercial alternatives: No licence cost, no subscription, no vendor lock-in Runs on any spare x86 PC or common hypervisor Web-based admin interface — no command-line expertise needed Open-source and auditable — in active development since 2002 ISP router requires no reconfiguration CacheGuard installs from a single ISO in under an hour and is suitable for offices, schools, branch networks, and home labs.