DefLang returns the default language.

GetLang returns the first language from accept-language.

IsLang checks if there is a language with code name.

LangMacro replaces all inclusions of $resname$ in the incoming text with the corresponding language resources, if they exist.

LangText looks for the specified word through language sources and returns the meaning of the source if it is found.

UpdateLang updates language sources for the specified state.

LangList is the list of available languages.