In the context of cooperative endeavors with Filipino scholars, institutions and language communities, SIL research on Philippine languages has been a part of' the development of linguistics as a discipline in this country since the early 1950s. SIL researchers have addressed such basic questions as: 'What Philippine languages are there?' and 'What are these languages like?' An analysis of Sll's academic and vernacular publications over the past fifty years reveals several areas of concentration. Particular contributions in the area of morphosyntax, discourse studies and lexicography are considered, and the variety and amount of literature produced in Philippine 'endangered languages' is highlighted. Some suggestions are given for future research.