Chip-scale frequency comb sources are key elements for a variety of applications, comprising massively parallel optical communications and high-precision optical metrology. In this talk, we give an overview on our recent progress in the area of integrated optical comb generators and of the associated applications. Our experiments cover modulator-based comb sources, injection locking of gain-switched laser diodes, quantum-dash mode-locked lasers, as well as Kerr comb sources based on cavity solitons. We evaluate and compare the performance of these devices as optical sources for massively parallel wavelength division multiplexing at multi-terabit/s data rates, and we report on comb-based approaches for high-precision distance metrology.