EuLisp

EuLisp is a statically and dynamically scoped Lisp dialect developed by a loose formation of industrial and academic Lisp users and developers from around Europe. The standardizers intended to create a new Lisp "less encumbered by the past" (compared to Common Lisp), and not so minimalist as Scheme. Another objective was to integrate the object-oriented programming paradigm well. It is a third-generation programming language.

Origin
The language definition process first began in a meeting in 1985 in Paris and took several years. The complete specification and a first implementation (interpreted-only) were made available in 1990.

Distinguishing features
Its main traits are that it is a Lisp-1 (no separate function and variable namespaces), has a Common Lisp Object System (CLOS) style generic-function type object-oriented system named The EuLisp Object System (TELOS) integrated from the ground up, has a built-in module system, and is defined in layers to promote the use of the Lisp on small, embedded hardware and educational machines. It supports continuations, though not as powerfully as Scheme. It has a simple lightweight process mechanism (threads).

Summary

 * A definition in levels, currently Level-0 and Level-1
 * Modules based on (non-first-class) lexical environments.
 * Lexically scoped, with dynamic or late binding available in Level-1.
 * A single name space for function and variable names (like Scheme).
 * Lightweight processes.
 * A fully integrated object system with single inheritance at Level-0 and multiple inheritance and meta-object protocol at Level-1.
 * An object-oriented condition system.

Implementations
An early implementation of EuLisp was Free and Eventually Eulisp (FEEL). The successor to FEEL was Youtoo (interpreted and compiled versions), by University of Bath in the United Kingdom. An interpreter for the basic level of EuLisp, level-0, was written by Russell Bradford in XScheme, an implementation of Scheme by David Michael Betz, originally named EuScheme EuScheme but the most recent version is renamed EuXLisp to avoid confusion. Also Eu2C, a EuLisp optimizing compiler, was created by Fraunhofer ISST under the APPLY project in Germany.

A dialect of EuLisp was developed, named Plural EuLisp. It was EuLisp with parallel computing programming extensions.

Example
Example use of classes in the algorithm to solve the "Towers of Hanoi" problem.