OST is intended to allow people searching for "open source textures" to easily find examples of such.
It is a simple web page that contains some thumbnails and titles that link to texture sections on actual content host websites.
Its use is questionable, considering that as of 2012-05-07 google.com/search?q=open+source+textures lists a Free Gamer blog post and OpenGameArt's texture section (which is great!) but not OST.
All in all, I had fun creating this little gallery. :)