In this chapter, Application Specific Instruction Set Processors (ASIP) will be introduced and discussed for readers who want general information about ASIP technology. The introduction includes ASIP design flow, source code profiling, architecture exploration, assembly instruction set design, design of assembly language programming toolchain, firmware design, benchmarking, and microarchitecture design. Two examples, design for instruction set level acceleration of radio baseband, and design for instruction set level acceleration of image and video signal processing, are introduced.