Can anyone recommend a spell checker for tex files?

[Taylor, P]

Peter Flynn wrote:

> detex on CTAN should run under Windows. This strips TeX commands, and
> leaves you with the plain text.  Or use Pandoc.

Given that TeX's output need not be in 1:1 correspondence with its 
input, would it not be better to apply spell-checking to the typeset 
output rather than the raw input ?
For example :

     \def \reorder #1#2#3 {#1#3#2}
     \reorder Nwo
     \end

Stripping out the markup would yield "Nwo", which would not occur in a 
British English dictionary; however, the DVI/PDF output will contain 
"Now", which would.
Philip Taylor