If you use Vim you've no doubt seen the steaming piles of poo it leaves in your working directories.
For example if you open foo.txt in Vim, it creates foo.txt~ in the same directory. I probably see the tilde as a pile of poo because I own a dog. Now that I've said it, you will see it as poo too. You're welcome.
In addition to the ~ file, it will also create a .foo.txt.swp file.
In some cases this is no problem. If you are working on code it may or may not be a problem.
