Atmel's popular In-System Programmable (ISP) FPGA Configurator EEPROM memories can be used with any SRAM-based FPGA from any supplier, including Atmel's own AT00 and AT40K FPGA's, as well as products from Xilinx, Altera, Vantis and Lucent. They come in densities from 65K to 2 Mb and are reprogrammable at 5V or 3.3V.