Two distinct populations of LMXBs were known from the Milky Way: field LMXBs believed to be formed from primordial binaries and globular cluster LMXBs believed to be formed in dynamical encounters. We find that the luminosity functions are different with a clear lack of faint sources in the globular clusters. We discovered a third population of LMXBs in the dense central regions of galaxies. Their spatial distribution indicates a dynamical origin and their luminosity function is consistent with the one of globular cluster LMXBs. From an evolutionary point, single-degenerate SNIa progenitors are similar to LMXBs. It is therefore likely that they too can be formed dynamically in globular clusters, and we are currently searching for observational signatures of this.