Depending on your system, the word separator characters change the way you can select/delete a word (e.g. by double clicking on it or using a key combination with your keyboard).
The fact is that I hate the default behavior of OSX.
For example:
Take the following line of code:
obj.attr1.innerAttr
If my cursor is at the end of the line and I press alt+backspace, it will delete everything and not just innerAttr.
I only found some apps (like iTerm) which let you change the word selection separator characters.
Is there a way to change it for the whole system?

