(S (S (S (NP (BASENP (NNP Microsoft) (POS 's)) (BASENP (NNP Internet) (NNP Explorer) (NNP 6))) (VP (VP (VBZ is) (NP (BASENP (NN one)) (PP (IN of) (BASENP (DT the) (ADJP (RBS most) (JJ successful)) (NN software) (NNS products))))) (ADVP (RB ever)))) (SBAR (IN as) (S (VP (VBN measured) (PP (IN by) (NP (BASENP (PRPD its) (NN durability)) (CC and) (NP (BASENP (DT the) (JJ massive) (NNS numbers)) (PP (IN of) (NP (BASENP (NNS people)) (SBAR (WHNP (WP who)) (S (VP (VBP have) (VP (VBN used) (BASENP (PRP it))))))))))))))) (PERIOD .))