licitly designed to avoid TCP-over-TCP issues.

chisel

- SSH under the hood, but still uses a custom client binary. Supports auto certs from LetsEncrypt. Written in Go.

bore

- Minimal tunneling solution. MIT Licensed. Written in Rust.

rathole

- Similar to frp, including the config format, but with improved performance. Low resource consumption. Hot reload. Written in Rust.

expose

- ngrok alternative written in PHP.

sish

- Open source ngrok/serveo alternative. SSH-based but uses a custom server written in Go. Supports WebSocket tunneling.

go-http-tunnel

- Uses a single HTTP/2 connection for muxing. Need to manually generate certs for server and clients.

pgrok/pgrok

- A multi-tenant HTTP reverse tunnel solution through SSH remote port forwarding.

tunnelto

- Open source (MIT). Written in Rust.

wstunnel

- Proxies over WebSockets. Focus on proxying from behind networks that block certain protocols. Written in Haskell with executables provided.

boringproxy

- Designed to be very easy to use. No config files. Clients can be remote-controlled through a simple WebUI and/or REST API on the server.