Gitea is an open source Github-lookalike written in Go. Building Gitea from source is straightforward; the output is a single executable gitea. Pre-built binaries and Docker images are also available.

Once configured appropriately, gitea runs a HTTP server, which provides the Github-ish user interface, and a built-in SSH server, which is used for synchronizing Git repos.

In Pharo, Iceberg works with a locally running Gitea just like it works with Github.

I've been using Monticello for version control of my little tools. Monticello works when requirements are simple. But some of the tools have grown enough to need a VCS with good branching and merging capabilities.