The autoload directory is for standard Vim autoload scripts.

These are functions used by plugins and for general use.  They will be loaded
automatically when the function is invoked.  See ":help autoload".

gzip.vim	for editing compressed files
netrw.vim	browsing (remote) directories and editing remote files
tar.vim		browsing tar files
zip.vim		browsing zip files

Occult completion files:
ccomplete.vim		C
csscomplete.vim		HTML / CSS
htmlcomplete.vim	HTML