Ruzsa (/ˈruʒɒ/) is an educational software for introductory logic courses. It's an analytic tableau proof editor for Tarski's World. Thus, Ruzsa is an alternative to Fitch, but instead of Fitch's natural deduction proof method, Ruzsa uses the more beginner-friendly method of analytic tableaux.
Available at https://ruzsa.tbitai.me, Ruzsa is free and open-source software.
Ruzsa is used at the Department of Logic at Eötvös Loránd University. It was named after Imre Ruzsa, the founder of the department.