... I send out a list of most interesting libraries and apps in the "Go" section to about 1100 subscribers.
Do you want it too?
Reverse proxy with simple routing configuration and override behaviour
WebSocket reverse proxy handler for Go
Small fast HTTP forward proxy in Go.
glider is a forward proxy with multiple protocols support, and also a dns forwarding server with ipset management features(like dnsmasq).
Go middlewares for HTTP servers & proxies
A simple, explicit forward proxy written in Go to facilitate HTTP CONNECT Tunneling.
An HTTP proxy library for Go