I always was interested why PostgreSQL client library named “libpq”. Of course I guessed that “lib” means “library”, but there are two more characters left. I supposed that “p” is some how connected with “Postgres”. But I have no any idea why “q” appeared in the library name.
Now I know the answer. Thanks to Bruce Momjian:
Libpq is called ‘libpq’ because of the original use of the QUEL query language, i.e. lib Post-QUEL. We have a proud backward-compatibility history with this library.