The Unix philosophy
- Each program should do one thing and do it well.
- Programs can be chained with pipes: the output of one is the input of the next.
- Text input and output as a universal interface.
The C language
Ritchie created the C language and Unix was rewritten in it. The operating system could then be moved to a different type of computer, which was unusual at the time. Universities got Unix cheaply, and a whole generation of computer scientists grew up on it.
The year 1970 and the year 2038
Unix counts time in seconds since 1 January 1970. Older systems store this number in 32 bits, which will overflow on 19 January 2038. Most systems have already been fixed, but the problem may still pop up in embedded devices.