Text::Aspell is a good module, and I recommend it highly. Also, I think mayhem may be misunderstanding the situation regarding forking. Text::Aspell does not fork: it is an XS module. You should use Text::Aspell if you are using GNU Aspell 0.50 or above. This has been the only officially supported version for over 2 years now so I recommend that. If you need to use an older aspell, then you would want the Text::Pspell module. That is the difference between the two.

Update: Calling the MS Word spell-checker through OLE is a particularly bad idea not only for system-dependency and reliability issues, but also because it is a violation of the Microsoft EULA.

Update: On prompting from Mr. Muskrat, I am now trying to find a reference for the claim I make in the above paragraph. I can't find one. If you know of one please help me out.