[SEJeff]

Your easiest bet is probably devpi, but you can download the cheeseshop code that powers pypi as well.

I'm using cheeseshop, but some people swear by warehouse, which is supposedly a legacy-free version for running pypi eventually.

If you don't care about the search api, you can also just enable an directory listing index page and use any web server. Pip will do the right thing when given the right incantation of magical arguments and you make a prayer to the pip gods.