Unix's License Changes

Earliest license:
`Here's your RK05, love Dennis'
By 1975, universities could get Unix with reasonable license conditions
By 1979, AT&T realised that Unix was a product, & tightened license restrictions
stopped the use of Unix to teach OS
This had the effect of creating GNU
GNU's not Unix
Also helped convince CSRG to decontaminate the 4BSD releases in the 1980s