ALF
   Foundation: Horn clause logic with equality which consists of predicates and Horn clauses for logic programming, and functions and equations for functional programming. A full integration of both programming models, so any functional expression can be use
   http://www.informatik.uni-kiel.de/~mh/systems/ALF.html

BABEL
   Operational semantics based on lazy narrowing; provides some higher-order features.
   http://www-i2.informatik.rwth-aachen.de/Research/BABEL/

Curry
   Multiparadigm declarative programming language seamlessly merges functional, logic, and concurrent programming paradigms; covers the most important operational principles in the area of integrated functional logic languages.
   http://www.informatik.uni-kiel.de/~curry/

Escher
   Declarative, general-purpose language, merges best features of functional and logic languages. Has types and modules, higher-order and meta-programming facilities, declarative input/output. Set of system modules provides many operations on standard data t
   http://www.cs.bris.ac.uk/~jwl/escher.html

Functional Logic Programming
   Michael Hanus's pages on amalgamating functional and logic programming.
   http://www.informatik.uni-kiel.de/~mh/FLP/

HAL
   Strongly typed, weakly moded, constraint-logic functional language designed to support construction, extension, and use of new constraint solvers.
   http://www.csse.monash.edu.au/~mbanda/hal/

LPG
   Generic functional logic language: functions defined by conditional rewrite rules, predicates defined by Horn clauses whose bodies may contain equations, disequations, or classical atomic formulae. Extant version uses extension of SLD-resolution merged wi
   ftp://ftp.imag.fr/pub/labo-LSR/SCOP/LPG/

RELFUN
   Relational-Functional Language: logic-programming language with call-by-value (eager) expressions of non-deterministic, non-ground functions; clauses are Hornish, succeeding with true(s), or footed, returning any value(s), and define operations (relations
   http://www.dfki.uni-kl.de/~vega/relfun.html