Lua scripts can be used to define actions for darktable to perform when an event is triggered. One example might be calling an external application during file export in order to apply additional processing steps outside of darktable.
Lua is an independent project founded in 1993, providing a powerful, fast, lightweight, embeddable scripting language. Lua is widely used by many open source applications, in commercial programs, and for games programming.
darktable uses Lua version 5.3. Describing the principles and syntax of Lua is beyond the scope of this usermanual. For a detailed introduction see the Lua reference manual.
The following sections will provide you with a brief introduction to how Lua scripts can be used within darktable.