Not surprisingly, for a long time (and to some extent even today) it is often highly classified. That is because the original use was for nuclear weapons which

Not surprisingly, for a long time (and to some extent even today) it is often highly classified. That is because the original use was for nuclear weapons which carried more than one warhead and could hit multiple targets (or one target really hard). That said, these days its somewhat standardized (see this brochure :https://www.moog.com/content/dam/moog/literature/Space_Defense/spaceliterature/structures/sais_payload_adapter_rev_0813.pdf https://www.moog.com/content/dam/moog/literature/Space_Defen...) Basically a kinetic mechanism, sometimes a spring, sometimes just gas (aka compressed air), is used to give each satellite a 'kick' when it is released. Once the satellite is unfolded and oriented it can use an on board thruster to move itself to the proper orbit.