(S (S (NP (BASENP (NNP Mark) (NNP Zuckerberg)) (PRN (COMMA ,) (NP (BASENP (NNP Facebook) (POS 's)) (NN CEO)) (COMMA ,))) (VP (VP (VBD announced) (NP (BASENP (DT the) (NN company) (POS 's)) (QT (DQL ``) (BASENP (NNP Open) (NNP Compute) (NNP Project)) (DQR '')))) (PP (IN at) (NP (BASENP (DT an) (NN event)) (VP (VP (VBN held) (PP (IN for) (BASENP (NNS reporters)))) (PP (IN at) (NP (NP (BASENP (DT the) (NN company) (POS 's)) (NNS headquarters)) (PP (IN in) (NP (BASENP (NNP Palo) (NNP Alto)) (COMMA ,) (BASENP (NNP California))))))))))) (PERIOD .))