The Barcza System is a interesting formation that is kind of like a reversed King's Indian defense, and it can become a King's Indian attack, which is one of its main lines.
Here is the bare bones of the formation:White can reach this position by some different move orders, although I personally prefer doing 1.Nf3 2.g3 3. Bg2 4.0-0
White for the most part doesn't care about what black does while he does his formation.
Black's best try to defeat this formation is the London defense:Another try is the reversed Kings Indian defense.
It is a rather quite and simple system that works really well! If you don't want to waste 10 hours studying the Ruy Lopez and the Queen's gambit, you should try this, because you can study and get good at it easily!
Hope you had fun and enjoy!