There's just no better text problem finder than a wordprocessor. For example I have found many instances of unintended double word error (e.g. wear and and tear) by copying a page of mine and pasting it to a work processor. Another error word processor do well is not recognizing obscure words (e.g. finding a spelling error when it see the word "wight" when you wanted to use the word "weight".).
But I have too many web pages to copy each ome and paste each one by one into a wordprocessor, and I make chages to the pages all the time. How can I copy all of my web pages and paste them into my wordprocessor? I looked through Firefoxes add-ons but couldn't find anyhting.