A fun one: PostgreSQL uses an adopted version of Tcl's regular expression engine, written by Henry Spencer. Tom Lane seems to think it was an impressive piece o

A fun one: PostgreSQL uses an adopted version of Tcl's regular expression engine, written by Henry Spencer. Tom Lane seems to think it was an impressive piece of work, and patched it up from time to time. https://en.wikipedia.org/wiki/Henry_Spencer https://en.wikipedia.org/wiki/Henry_Spencer https://en.wikipedia.org/wiki/Tom_Lane_%28computer_scientist%29 https://en.wikipedia.org/wiki/Tom_Lane_%28computer_scientist...