This paper reports about the 2005 comparative evaluation of solvers for quantified Boolean formulas (QBFs), the third in a series of non-competitive events established with the aim of assessing the advancements in the field of QBF reasoning and related research. We evaluated thirteen solvers on a test set of more than three thousands QBFs, selected from instances submitted to the evaluation and from those available at www.qbflib.org. In the paper we present the evaluation infrastructure, from the criteria used to assemble the test set to the hardware set up, and we show different views about the results obtained, highlighting the strength of different solvers and the relative hardness of the instances included in the test set.