A bit of History and Background

The original computer languages were so-called machine languages: human and computer programmed in same language
machine language is great for computers but not great for humans
High-level languages introduced for ease of programmability
Fortran was the first high-level language: 1956, Backus
A Swarm of early languages followed: Lisp in early 60's, ALGOL in '58, PL/1 in late 60's, BASIC in 1966.

Tiers of language evolution

Machine language
FORTRAN, BASIC, C, Pascal, etc: first-order programmability
Lisp, Scheme, ML: higher-order programmability, automated allocation and garbage collection, memory-safe; ML is strongly typed.

Object-oriented languages paralleled this hierarchy:

First, passing objects is passing code which is similar to passing functions -- elements of higher-order functional programming to pass and return objects, but no creating them on the fly. More powerful than C's function pointers, objects have "their" state with them and function passing doesn't.
Simula67: original O-O language, created for simulation. FORTAN-like otherwise. C++ is another basic O-O language.
Smalltalk in the late 70's: Lisp-inspired version of O-O which also pushed ahead greatly the concept of object-oriented programming. Includes implicit allocation and garbage collection, explicit higher-order functions, others. Squeak is a Smalltalk dialect; Ruby is "Smalltalk++"
Java improves on Smalltalk by being typed and more secure plus a better module system.

Domain-specific programming languages (DSL's)

Also, some languages aren't for general programming at all

Last modified: Fri Feb 9 11:28:47 EST 2007