Junk mail database and tar-pit

Junk mail repository
Prolog FAQ
Using a home-made supercomputer to analyse Texas Holdem
Edison compiler/interpreter: Edison is the RISC epitome of concurrent languages. Per sure works hard at making life simple. ;-)
Anagram generator (Webster's)
Simple constraint solver
Simple knight's tour in Prolog -- no matrixes!
Simple maze solver
Peg Solitaire in Prolog
Simple BB instruction scheduler
Speed performance
Compiler for dataflow arch
FPGA compiler/simulator
VLSI layout robot
Warren's WARPLAN planner (from 1974)
New high-performance f90 compiler for desktops
Compiling Prolog into SQL: No, I don't mean "Prolog queries into SQL queries". A self-compiling Prolog compiler into SQL. Or sed, awk, csh, or perl.
Compiling Prolog into Yacc
Prolog RPC compiler: Intended use -- convert specification for monolithic O/S into lightweight distributed version of itself. Better than doing it by hand.