In this review talk, I will walk through the most common complications when building a transmission spectrum (as a reminder from the hands-on workshop earlier in the week). I will then highlight the most important results of recent years in the realm of narrow-band transmission spectroscopy using high dispersion spectra with a focus on the different spectrographs currently capable of these works. I will then move on to provide an outlook into which instruments will or might be used in the near future to perform transmission spectroscopy. Lastly, the different uses of resolved spectral lines in studying exoplanet atmospheres are explored in an outlook.