Revel
A high productivity, full-stack web framework for the Go language
... the freedom to replace the default filters with custom implementations. Already have an application started ? No problems, migrate easily to Revel by passing the path that you want your mux to handle to Revels Mux, and all requests for that path will be passed to that your Http muxer. Revel has modules. These are reusable MVC components that you can implement across all your projects. No need to copy and paste your code with these.