frp

Frp (Fast Reverse Proxy) creates a tunnel from your local machine to a public server. Think ngrok, but you run the server yourself and pay nothing.

Apache 2.0 license, written in Go. You run frps (server) on a VPS with a public IP, and frpc (client) on your local machine. Configure which local ports to expose, and frp handles the tunneling. Supports TCP, UDP, HTTP, HTTPS, and STCP (secret TCP for peer-to-peer). Dashboard included for monitoring connections.

Fully free. No paid tier, no hosted version. You bring your own VPS. Setup: get a cheap VPS ($3-5/mo), install frps, configure frpc on your local machine. Takes about 15 minutes. Ongoing ops: almost none. frp is a single binary that just runs.

Solo developers: perfect for exposing local dev servers, home lab services, or self-hosted apps. Small teams: works well for sharing internal services. The catch: you need a VPS with a public IP, which means some cost and basic server knowledge. The config file format is straightforward but not as instant as `ngrok http 3000`. And there's no built-in auth or rate limiting on exposed endpoints; you handle security yourself.