In this session, we'll create a new programming language called DevoxxLang! We'll construct its grammar, semantics, operations and the interpreter for the language. Additionally, we'll learn about parsers and how to perform simple optimizations, both at compile time and otherwise. Most importantly we'll tackle the interoperability problem with the underlying platform, which in our case is the JVM. This session will briefly discuss type systems, optimizations, memory management and concurrency issues that programming languages all encounter. Have you ever wanted to create a programming language of your own? After this session, you will have seen all the tools you need to do so and will understand more about how are programming languages work including the challenges you’ll face. Oleg Šelajev is an engineer, author, speaker, lecturer and advocate at ZeroTurnaround. He spends his time testing, coding, writing, giving conference talks, crafting blogposts and reports. He is pursuing a PhD on Dynamic System updates and code evolution. Oleg is a part-time lecturer at the University of Tartu and enjoys speaking and participating in Java/JVM development conferences such as JavaOne, JavaZone, JFokus and others. In his free time, Oleg plays chess at a semi-grandmaster level, loves puzzles and solving all kinds of problems. [CQZ-1658]