Chip-scale frequency comb sources have the potential to revolutionize future terabit/s telecommunication. Mathematically, frequency combs are modeled by stationary solutions of a nonlinear Schrödinger equation with a damping and a forcing term. Specific material properties are described by additional terms or equations. It is crucial for applications to characterize those regions of the parameter space where frequency combs exist which are stable under small perturbations. In this project, the occurrence of stable frequency combs is analyzed with techniques from bifurcation analysis, and their formation is simulated with splitting methods. This is complemented by comb generation experiments with microresonator samples.