Templates, external code symbols and menu labels can be resolved differently depending on language.
This is enabled by the Execution context of the engine. Through the context, the current language, if set, is always available to client code.
Language specification is encapsulated by the lang module, using the ISO639 language identifier standard.
The default language can be set in engine.Config.Language.
It may also be set as a side-effect of bytecode execution. This is done by executing LOAD with a symbol returning an ISO639 language code, while setting the LANG signal flag (see Built-in signal flags.