brew install boot-clj
boot -u
git clone https://github.com/addplus/learn-datalog.git
cd learn-datalog
boot dev

This starts an nREPL server and a client and loads the example learn-datalog namespace.

While you can type in the terminal at the prompt opened by boot dev, for convenience I would recommend creating a Remote nREPL configuration in IntelliJ with the "Use Leiningen REPL port" option.

Afterwards pressing Cmd+R will connect to the already running nREPL process. Then just open the learn_datalog.clj, position into the middle of any of the query expressions and press Cmd+Shift+P to send it to the REPL.

Enjoy, until the original site is back up again.

The original Learn Datalog Today is broken at the moment @fasiha recommended to use a DataScript environment to allow running the example queries. This repo just packages up that code.

Thanks, @fasiha!