Quaffle: Quantified Boolean Formula Evaluator with Learning Quaffle is an experimental QBF solver. The idea of this solver is described in the following two papers: L. Zhang and S. Malik, ”Towards Symmetric Treatment of Conflicts And Satisfaction in Quantified Boolean Satisfiability Solver”, Proceedings of 8th International Conference on Principles and Practice of Constraint Programming (CP2002). Ithaca, NY, Sept. 2002. [PDF] L. Zhang and S. Malik, ”Conflict Driven Learning in a Quantified Boolean Satisfiability Solver”, Proceedings of International Conference on Computer Aided Design (ICCAD2002), San Jose, CA, Nov. 2002. [PDF] Source code for Quaffle is available for download here . Please read the lincence agreement on the top of each file. The code is experimental and for algorithm evaluation only. It should compile under most Unix/Linux machines using g++. The run time comparison of Quaffle with two other state of the art QBF solvers QuBE and Semprop is available here. The benchmarks are obtained from QBFLib. The experiments were carried out on a Dell PowerEdge 1500sc with 1133Mhz PIII CPU and 1G memory. Time out limit is 600 seconds.