So, to differ from the argumentum ad populum, a language is relevant if it effectively provides results. COBOL is still effectively producing results, so it is certainly relevant to those using it. An otherwise effective language can lose relevance if not maintained to the point where it won't run on the operating systems people use. People are more likely to change operating systems than re-write a successful custom application program. Open source languages minimize this risk by allowing virtually anyone to alter and re-compile them; adherance to programming standards reduce the chances that the source code will require alteration.