Simon is a lightweight self-hosted system monitor that shows live CPU, memory, disk, and network metrics for your server and its Docker containers in one web dashboard, with threshold alerts and a built-in file browser. Open the dashboard to watch real-time gauges alongside historical charts, so a slow memory leak becomes visible hours before it takes a service down. Every running container appears with its own CPU and memory stats, and its logs open in a searchable viewer, so routine diagnosis never needs a terminal session on the host. The file browser lets you navigate the directories you choose to expose, preview file contents, upload with drag and drop, create folders, and move or delete items. Downloads support range requests, which means large files resume cleanly after a dropped connection and media files stream instead of failing halfway. Alert rules fire when CPU, memory, disk, or network activity crosses thresholds you set, and notifications arrive through Telegram, ntfy, Gotify, Pushover, Pushbullet, Matrix, or any custom webhook. Prebuilt notification templates get common setups running in minutes, and password authentication keeps the dashboard private on a public server. Resource-constrained machines benefit most: the monitor runs comfortably on single-board computers and small instances where heavier monitoring stacks would consume the very memory they exist to watch. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.