This is a Blender addon allowing you to export static meshes to the now-defunct ASE (ASCII Scene Export) format still in use in legacy programs like Unreal Tournament 2004.
Check out this video on how to install and use the addon.
Resources:
DarklightGames/io_scene_ase
A Blender add-on for exporting ASCII Scene Export (ASE) files
PythonGPL-3.0