This document summarizes Phillip Trelford's 2014 talk at NDCLondon about creating domain specific languages and compilers. It discusses abstract syntax trees, parsing, interpreters, and code generation. It provides examples of turtle and Small Basic languages and their abstract syntax trees. It also mentions that the speaker created a basic C# compiler in 24 days to demonstrate that compilers can be written quickly without extensive experience. The document encourages attendees to learn from online resources like F# Koans and TryFSharp.org, and recommends buying related books.