Results from ab initio calculations at the CCSD(T) level of theory are presented for krypton monofluoride (KrF), krypton monofluoride cation (KrF+), linear, ground-state krypton difluoride (KrF2), the triplet state of krypton difluoride, and the krypton-fluorine van der Waals complex (Kr-F-2). These are the first calculations demonstrating that KrF is a bound molecule, in agreement with experimental observation. When corrected for basis-set superposition error, the calculated potential displays quantitative agreement with the attractive wall of the experimentally measured potential curve. Results are also presented for KrF+ and linear KrF2 which yield accurate values for their dissociation energies, The tripler state of KrF2 is found to have a minimum energy below that of separated atoms, and its structure is bent, with a small F-Kr-F bond angle (71 deg). The van der Waals complex, Kr-F-2, appears to consist of an unperturbed F-2 molecule attached to a krypton atom in the expected T-shaped structure.