TF2 blueprints and custom crafted weapons

I was on this website which allows you to see blueprints and see what weapons people have in TF2 when I came across the "Community Knife".

What is it and how do you make it? http://www.tf2items.com/id/df

Also here is a list of blueprints: http://www.tf2items.com/crafting/blueprints.php