sing-box

sing-box is a universal proxy platform written in Go. Its documentation site describes installation through package managers, Docker or building from source, graphical clients for Android, Apple platforms and desktop, and a manual covering both server and client configuration. GitHub lists the license as 'Other', so check the repository for the terms.

The configuration is JSON based and organized into sections for logging, DNS, NTP, certificates, routing and experimental features. DNS supports many server types and rules, including FakeIP, and routing covers GeoIP, Geosite, rule sets, protocol sniffing and rule actions. The proxy section documents protocols such as Shadowsocks, Trojan, Hysteria 2 and AnyTLS, and the experimental section includes Clash API and V2Ray API compatibility.

A JSON schema is available for editors, and a changelog and migration guides help when upgrading between versions. Because it is flexible and low level, sing-box suits advanced users, network administrators and developers who want to build custom proxy setups, and who are comfortable reading configuration documentation.