There are many methods to solve ordinary differential equations, but what about systems of ODEs?
So far I've seen only two methods mentioned in this context: Euler's and Runge-Kutta 4th order. Both of them calculate new $y_{i,n+1}$ based only on set of $y_{*,n}$ from the previous iteration.
So are there other numerical methods to solve (possibly non-linear) systems of differential equations?