{Fly me to the moon: \AllTeX\ testing (and more) using~Lua} {Joseph Wright} {Testing has been important to the \LaTeX\ team since its inception, and over the years a sophisticated set of test files have been created for the kernel. Methods for running the tests have varied over the past quarter-century, following changes in the way the team work. In recent years, the availability of Lua as a scripting language in all \TeX\ systems has meant it has become the natural choice to support this work. With this as a driver, the team have developed \code{l3build} for running tests automatically. Building on the core work, \code{l3build} has grown to provide a powerful approach to releasing packages (and the LaTeX kernel) reliably. Here, I'll look at the background of our testing approach, before showing how and why Lua works for us~here.}