Lumina is an (attempt) at creating a small, performant library for interacting with FINAL FANTASY XIV game data in a convenient manner.
See the Lumina.Example
project for more comprehensive examples on loading files and creating custom data types.
var lumina = new Lumina( "path/to/sqpack/folder" );
var file = lumina.GetFile( "exd/root.exl" );
file.SaveFile( "root.exl" );