Historically, operating system development and programming language development went hand-in-hand. Challenges in one area were often approached using ideas or techniques developed in the other, and advances in one area enabled new capabilities in the other. Today, although the systems community at large retains an iron grip on C, modern programming language ideas continue to spark innovations in OS design and construction. Conversely, the systems field continues to provide a wealth of challenging problems and practical results that should lead to advances in programming languages, software designs, and idioms. This workshop will bring together researchers and developers from the programming language and operating system domains to discuss recent work at the intersection of these fields. It will be a platform for discussing new visions, challenges, experiences, problems, and solutions arising from the application of advanced programming and software engineering concepts to operating systems construction, and vice versa.