This site is concerned with the 2nd wave of FPGA cryptomining that started to gain traction in mid-2018 (Field Programmable Gate Arrays). For context, some information on earlier FPGA efforts in the cryptomining space are presented.
Around 2011 some miners started switching from GPUs to FPGAs, (Field Programmable Gate Arrays), after the first implementation of Bitcoin mining came out in Verilog, (a hardware design language that’s used to program FPGAs).
FPGAs can get close to the performance of custom hardware (e.g. ASICs) while also allowing the owner of the card to customize it or reconfigure it "in the field".
ASIC chips are designed in a factory and do the same thing forever. FPGAs offer better performance than graphics cards, particularly on “bit fiddling” operations which are trivial to specify on an FPGA.
Cooling is also easier with FPGAs and, unlike GPUs, you can theoretically use nearly all of the transistors on the card for mining. Like with GPUs, you can pack many FPGAs together and drive them from one central unit, which is exactly what people began to do.