{\LaTeX3: From local to global\Dash a brief history and recent~developments} {Will Robertson \& Frank Mittelbach} {The original source code for \LaTeX3 dates to the early 1990s. Key aspects of its development occurred during that decade, but it was not until the late 2000s that the project began delivering code that was widely used by mainstream \LaTeX\ users. What happened in this time? This talk will discuss how \LaTeX3 development evolved over the decades and how it reached a state of being used to produce real users' documents whether or not they are actually aware of it. \LaTeX3\ can be thought to consist of separate `layers', and the programming layer known as \code{expl3} is starting to be used to solve problems in and write packages for \LaTeXe. Our plans are not restricted to such `under-the-hood' measures, however, and we have discussed layers of \LaTeX3 that will have more visibility at the user interface. Our talk will discuss these separate layers and where our plans lead in the future, and will conclude with a demonstration of what's new in the current code. }