Worth a re-link: Marc Garrett did a splendid, thoughtful interview with Mark Hamburg a little over a year ago when Lightroom first shipped, including this on their extensive use of the Lua scripting language:
Pretty much every piece of code in the app that could be described as making decisions or implementing features is in Lua until you get down to the raw processing, which is in C++. The database engine is in C; the interface to the OS is in C++ and Objective C as appropriate to platform. But most of the actually interesting material in the app beyond the core database code (which is SQLite) and the raw processing code (which is essentially Adobe Camera Raw) is all in Lua.
★ Wednesday, 30 April 2008