WebAssembly (Wasm) started out with a relatively simple low-level model of store that primarily consisted of an array of raw bytes representing a program’s memory. But in fact, this has never been the full story, even in the beginning. Moreover, over recent years, this model has evolved significantly, especially with the introduction of features like threads, garbage collection, multiple memories, and 64-bit address space. In this presentation, I will go into more details about what Wasm’s memory model was, has been morphed into, and is going to become, while busting some myths, explaining some of the unique challenges, and giving a glimpse of the scary future.

Andreas Rossberg is an independent researcher and engineer who has been oscillating between academia (Saarland University, Max Planck Institute for Software Systems) and industry (Google, Dfinity). By a few twists of fate, he became one of the designers of WebAssembly, author of its formalisation and specification, and champion of various proposals for enhancement. His research interests broadly revolve around programming languages, ranging from foundational theory, over design, to implementation, as long as they aren’t ugly.