A modified version of original Flagmatic-2.0
The original website Flagmatic.org is down, so I set up this temporary page. The latest version of Sage that I know Flagmatic runs on (and gives approximately correct answers) is Sage-9.5.
Flagmatic is a package for computing bounds for Turán type problems. The structures it supports are: graphs, 3-regular hypergraphs, directed graphs, and multigraphs. It was developed by Emil R. Vaughan while working with Victor Falgas-Ravry (see their paper). Flagmatic uses the flag algebra calculus introduced in Razborov in 2007.
The version of Flagmatic that this site links to is not Emil's original version -- that can be found here. This version includes changes introduced when working with Oleg Pikhurko.
See the README file in the Github repository. It gives a short and hopefully working sequence of steps to get Flagmatic set up with Sage.
You can find the original User Guide by Emil here.
The very first version of Flagmatic was Sage independent, and it is still hosted on its original website. The website contains a list of results obtained or re-obtained with Flagmatic and Flagmatic-2.0.
In 2013, Emil Vaughan (@emil79) wrote the original version of Flagmatic-2.0.