Links

Paradox — A Finite Model Finder for First Order Logic: Translates to SAT, and uses MiniSat as a backend.
The MathSat page: A project to build a framework for "Satisfiability Modulo Theories" (SMT), in which MiniSat is used.
sKizzo — A QBF Solver: sKizzo is a hybrid QBF solver that uses several techniques of mainly symbolic, but also search-based nature. MiniSat is used as a possible backend for propositional reasoning.
The ARIO SMT Solver: Another framework for SMT, developed at University of Michigan. MiniSat is rumored to be in there somewhere too.
DPvis — Visualizing the Davis-Putnam Procedure: A really cool visualizer for CNFs and for DPLL-search, put on top of MiniSat.
ABC: A System for Sequential Synthesis and Verification: Developed by the Berkeley Logic Synthesis and Verification Group. It uses the C version of MiniSat.
MiniSat(ID): A minisat-based SAT solver for an extension of CNF (with propositional inductive definitions, aggregates, pseudoboolean constraints).
IDP — a finite domain model generator for FO(.): Propositionalises FO(.) theories (typed first order logic with inductive definitions, aggregates, bounded arithmetic) and applies minisat(ID).

SAT Live: Currently the most active web forum for SAT.
The Propositional Satisfiability Web Site: Contains more links to material, in particular to the SAT conference.