Everything to get sharper, in one place
All free, all in the browser. The structured paths and daily quest live in the app — these are the open resources anyone can use.
Terminal Trials
A free browser-based Linux command-line game: 30 progressive challenges where you fix broken systems in a real (simulated) shell.
Concepts
Progressive explainers — ELI5 to deep dive — with diagrams: Kerberos, DNS, TLS, subnetting, TCP, containers and more.
Puzzles
Interactive troubleshooting: investigate with real commands, find the root cause, choose the safe fix.
Reference
Task-based recipes — 'find what's using a port', 'check why a service failed' — for when you just need the command.
Tools & calculators
23 browser tools: subnet & CIDR, chmod, RAID capacity, regex tester, base64, JWT, cron and more.
Skill diagnostic
A 10-minute assessment that places your level and recommends where to start.
Blog
Field notes for infrastructure engineers — troubleshooting mental models and hard-won lessons.