As advanced technology nodes continue scaling down into sub-16 nm regime, optical microlithography becomes more vulnerable to process variations. As a result, overall lithographic yield continuously degrades. Since next-generation lithography (NGL) is still not mature enough, the industry relies heavily on resolution enhancement techniques (RETs), wherein optical proximity correction (OPC) with 193 nm immersion lithography is dominant in the foreseeable future. However, OPC algorithms are getting more aggressive. Consequently, complex mask solutions are outputted. Furthermore, this results in long computation time along with mask data volume explosion. In this chapter, recent state-of-the-art OPC algorithms are discussed. Thereafter, the performance of a recently published fast OPC methodology-to generate highly manufactured mask solutions with acceptable pattern fidelity under process variations-is verified on the public benchmarks.