Complex sentence: Fred and Linda became a couple and devoted themselves to cryonics, formed a cryonics corporation (Manrise) and wrote the first detailed procedure manual for cryonics that had ever existed.
Split into simpler sentences: Fred and Linda became a couple and devoted themselves to cryonics. They formed a cryonics corporation (Manrise) and wrote the first detailed procedure manual for cryonics that had ever existed.