Edsger W. Dijkstra, Dutch computing scientist.
If you don't know him, read his books and articles. Also read BeautyIsOurBusiness.
See http://www.cs.utexas.edu/users/almstrum/cs373/general/EWD1166.html for an autobiography including his contributions to the development of compilers, and his run-in with Harry D. Huskey, inventor of the SWAC.
EWD Archive is at http://www.cs.utexas.edu/users/EWD/.
As a skilled writer and a master of language Dijkstra is the source of many memorable sayings, some of which are now consecrated as integral parts of the computer science lingo. The quotes which inspired or otherwise interested wikizens are on a separate page EwDijkstraQuotes
Links and Papers
Guidance on how to say his name moved to PronouncingDutch.