Erlang Programming Language
Might seem a bit strange at first, but when you actually try to write some code, it really is very nice. by Jan 9
The Haskell Programming Language Haskell is an advanced purely-functional programming language. An open-source product of more than twenty years of cutting-edge research, it allows rapid development of robust, concise, correct software.
GNU Smalltalk | The Smalltalk for those who can type
Overview (Java 2 Platform SE v1.4.2)