CryptoMiniSat is an award-winning SAT solver based on MiniSat. It brings a number of benefits relative to MiniSat, among them XOR clauses, extensive failed literal probing, and better random search.
The solver basically performs the following steps:
1) parse CNF file into clause database
2) run Conflict-Driven Clause-Learning DPLL on the clauses
3) regularly run simplification passes on the clause-set
4) display solution and if not used as a library, exit
Here is a picture of of the above process in more detail: