IPFire is a hardened, versatile, state-of-the-art Open Source firewall based on Linux. Its ease of use, high performance in any scenario and extensibility make it usable for everyone. For a full list of features have a look here.
This repository contains the source code of IPFire 2.x which is used to build the whole distribution from scratch, since IPFire is not based on any other distribution.
Just head over to https://www.ipfire.org/download
We have a long and detailed documentation located here which should answer most of your questions.
You can ask your question at our community located here. A complete list of our support channels can be found here.
We have another document for this. Please look here.