When I started college in 1989, my Pascal programming class used a cluster of AT&T 3B2 systems running SVR3. I poked around those systems like crazy over the course of two quarters. I don't remember if there was any significant source code exposed to unprivileged users.
During the mid-90s, the Unix Wars were raging and Unix System Labs was suing U.C. Berkeley over the intellectual property of Unix source code. Unix had been written at AT&T Bell Labs, but Berkeley had licensed and forked their own, based on improved networking code, and by this time it was ready to run on i386 systems. In fact, USL had borrowed back some BSD code, allegedly without crediting them. Berkeley had been busy removing AT&T code and replacing it, so they could relicense BSD Unix.
USL, part of AT&T (but later purchased by Novell), contended that Berkeley could not easily make a "clean room implementation" of any kernel code or device drivers, if those programmers had read or worked with original AT&T source code. They told the courts (and journalists) that the programmers might be tempted to reproduce proprietary Unix code, consciously or subconsciously, and therefore, these programmers were permanently "Mentally Contaminated" and Berkeley should not be allowed to continue distributing BSD [BSDi] Unix.
So when I attended Usenix LISA in 1994, this 3-year lawsuit was at a fever pitch, and someone on the convention floor had manufactured large buttons for attendees to wear, proudly proclaiming "MENTALLY CONTAMINATED", and all the admins and systems programmers had a good laugh about the absurdity of trying to keep a lid on proprietary source code by policing everyone who's ever seen one of its files.
joshuaissac
This type of restriction is still applied to contributors to the ReactOS project, in that contributions are not accepted from those who have seen any leaked Windows source code or have worked for Microsoft.
During the mid-90s, the Unix Wars were raging and Unix System Labs was suing U.C. Berkeley over the intellectual property of Unix source code. Unix had been written at AT&T Bell Labs, but Berkeley had licensed and forked their own, based on improved networking code, and by this time it was ready to run on i386 systems. In fact, USL had borrowed back some BSD code, allegedly without crediting them. Berkeley had been busy removing AT&T code and replacing it, so they could relicense BSD Unix.
USL, part of AT&T (but later purchased by Novell), contended that Berkeley could not easily make a "clean room implementation" of any kernel code or device drivers, if those programmers had read or worked with original AT&T source code. They told the courts (and journalists) that the programmers might be tempted to reproduce proprietary Unix code, consciously or subconsciously, and therefore, these programmers were permanently "Mentally Contaminated" and Berkeley should not be allowed to continue distributing BSD [BSDi] Unix.
https://en.wikipedia.org/wiki/UNIX_System_Laboratories,_Inc.....
So when I attended Usenix LISA in 1994, this 3-year lawsuit was at a fever pitch, and someone on the convention floor had manufactured large buttons for attendees to wear, proudly proclaiming "MENTALLY CONTAMINATED", and all the admins and systems programmers had a good laugh about the absurdity of trying to keep a lid on proprietary source code by policing everyone who's ever seen one of its files.