The paper "Modular Ontologies - A Formal Investigation of Semantics and Expressivity" by Jie Bao, Doina Caragea, and Vasant Honavar received the best paper award, sponsored by the Knowledge Web project of the European Network of Excellence and the Japanese Society for Artificial Intelligence at the First Asian Semantic Web Conference (ASWC 2006), held in Beijing, China, during September 3 through September 7, 2006. The paper introduced an abstract modular ontology Language to analyze the expressivity requirements, semantics, and reasoning procedures for modular ontologies and to compare several existing modular ontology language proposals. It also shows that P-DL, a new modular ontology language proposed by the authors, by relaxing the strict domain disjointedness assumed by distributed description logics (DDL) and E-connections, can overcome some of the known semantic difficulties of both DDL and E-connections. The paper appears in the conference proceedings published by Springer-Verlag (Lecture Notes in Computer Science, Voll 4185, pp. 616-631, 2006). The results presented in this paper form the basis of research on modular distributed ontologies being pursued in the Artificial Intelligence Research Laboratory in the Center for Computational Intelligence, Learning, and Discovery at Iowa State University that was recently funded by the National Science Foundation. They build on other ongoing research in the lab on knowledge acquisition from semantically heterogeneous, distributed information sources. Modular ontologies and the associated distributed reasoning algorithms constitute some of the key ingredients for the emerging semantic information integration, knowledge acquisition, and semantic web technolologies.