lua5.1-doc 5.1.5-8.1build2 (amd64 binary) in ubuntu cosmic

 Lua is a powerful, light-weight programming language designed for extending
 applications. The language engine is accessible as a library, having a C
 API which allows the application to exchange data with Lua programs and also
 to extend Lua with C functions. Lua is also used as a general-purpose,
 stand-alone language through the simple command line interpreter provided.
 .
 This package contains the official manual covering the Lua language and C API,
 examples, etc.