Flyspell enables on-the-fly spell checking in Emacs by the means
of a minor mode. It is called Flyspell. This facility is hardly
intrusive. It requires no help. Flyspell highlights incorrect words
as soon as they are completed or as soon as the cursor hits a new
word.

Flyspell is language independent because you are free to select
your own dictionary.

Flyspell is compatible with TeX editing. That is, Flyspell tries,
as much as possible, to avoid highlighting TeX command.

Flyspell proposes corrections for miss-spelled words by the means
of pop-up menus. Alternatively you will be able to store the word
in the global dictionary, to add it to the current document dictionary
or to ignore the miss-spelling for the current session.

Flyspell also proposes automatic corrections.