Explorer-reader.vim is a project mainly written in Vim Script, it's free.
preview many text files quickly
This is a mirror of http://www.vim.org/scripts/script.php?script_id=1227
with this script you can quickly preview files in a directory. For example execute these commands in a directory with many text files :cd dir_with_many_text_files :vi . or :vi dir_with_many_text_files then by pressing page down you will preview files. Pressing down will scroll the preview one line at a time and pressing page down while on the preview it will focus on the explorer window