Excitation functions of all stable or long-lived krypton isotopes were measured or estimated for incident protons and neutrons in Rb, Sr, Y, and Zr targets. Experimental data concern mostly Y and Zr targets bombarded with 0.059 to 24 GeV protons. The products /sup 78en-dash86/Kr, /sup 74/As, /sup 75/Se, /sup 83,84,86/Rb, /sup 85/Sr, /sup 88/Y, /sup 88,95/Zr, and /sup 92/Nb/sup m/ were measured using high-sensitivity mass spectrometry and nondestructive ..gamma.. counting. Lighter products such as /sup 38,39,42/Ar and 12 radioactive isotopes from /sup 7/Be to /sup 65/Zn were also measured in some cases and their cross sections are given in an appendix. Most excitation functions pass through a maximum between 0.4 and 0.8 GeV, and the peak energy could depend on the ..delta..A value. The results, combined with a general survey of nuclear reactions in Ga to Nb targets, permitted the development of new systematics leading to the calculation of spallation-produced Kr isotopes in the moon bombarded with galactic and solar cosmic rays. Compared to cosmogenic krypton measured in nine well-documented lunar samples, /sup 83/Kr is predicted with a precision better than 33% (1sigma) and the production ratios /sup i/Kr//sup 83/Kr are predicted to better than 25%. It is concluded thatmore » the cosmogenic ratios /sup 86/Kr//sup 83/Kr and /sup 81/Kr//sup 83/Kr are dependent on the main target element concentrations. This should be taken into account in strontium-rich samples when calculating exposure ages of extra-terrestrial materials.« less