Process substitution is a great little feature and it feels very Unixy, but it took a surprisingly long time to appear in Unix and in shells. This is because it needed a crucial innovation, namely names in the filesystem for file descriptors, names that you can open() to be connected to the file descriptor.

m4 is a general-purpose macro processor included in most Unix-like operating systems.

A collection of modern/faster/saner alternatives to common unix commands.

The Unix Game is a programming contest where players solve coding challenges by constructing “pipelines” of UNIX text processing utilities to compute the solution.

Examples of SSH tunnels with a visual representation of the traffic flows.