language families:

array languages (APL, Nial, K, SETL, etc.)
logic languages (Prolog)
smalltalks
lisps
stack based/concatenative (Forth, Joy, Factor etc.)
functional(esque)
 - impure (OCaml etc.)
 - pure (Haskell etc.)
 - dependent types/theorem provers (Idris, Coq etc.)
C/Algol style (C, Java, JS, Python, Fortran etc.)
string manipulation (SNOBOL, TRAC, Icon etc.)
asms

~/languages/families.html