Despeller is a little utility, which disables the spellchecking throughout the system by replacing the image files which OS X (AppKit, to be precise) uses to underline wrong spelling. You can always restore the dots.
Important: Remember, this is a system file you're replacing, which means three things:
- You need to be admin to do this.
- This will effect all users. Make sure others don't use spellchecking.
- This is likely to be restored with every system update, so you'll need to run it every time after installing a system update.