This report presents fourth quarter 1999 (4Q99), second-half 1999 (2H99), and full-year 1999 (FY99) vendor market shares for the user programmable logic market, as well as specific product categories. Those product categories include simple PLDs (both Bipolar and CMOS), complex PLDs, and FPGAs. Fourth quarter data is compared to both 3Q99 as well as 4Q98. Half-year data is compared to both 1H99 and 2H98, while 1999 data is compared to 1998.