But is it free?

• UNIX is not free software

• work done at UCB was available without licensing conditions

• tapes contained both UNIX and UCB code, so only went to UNIX license holders

• CSRG worked to extricate the Berkeley code from the UNIX code in the late 80's

• results released as Berkeley Networking Tapes, Net/1, and Net/2 (not complete OSs but open source)