Sure, but look at the MIT AI Lab environment from whence it sprang: their PDP-10's ran ITS (the Incompatible Time Sharing system, a jab at the IBM 7090-based Co

Sure, but look at the MIT AI Lab environment from whence it sprang: their PDP-10's ran ITS (the Incompatible Time Sharing system, a jab at the IBM 7090-based Compatible Time Sharing System, CTSS), which was a completely open system. Anyone could create an account, and anyone could bring down the system with a few keystrokes (the terminal interface was an extended DDT, a single-keystroke-command-style debugger), and anyone could delete any file, including system files. They had a radical open system, and defended it (yes, it was early in the life of the ARPAnet/Internet) with great backups and social pressure. The LispMs were not much different.