OpenFPGA is an open-source framework that accelerates the development cycle of customizable FPGA architectures through various automation strategies. It allows users to define customized FPGA architectures using a high-level architecture description language and auto-generate the corresponding Verilog netlists that can be used in a backend flow to generate production-ready layouts. OpenFPGA also provides native bitstream generation support for user Verilog designs, avoiding recurring engineering costs in developing CAD tools for these customized FPGAs.