I know that there is probably no definitive answer, but
does it matter in search engine optimization whether you use PHP or ASP for your CMS.

Look forward to hearing your ideas.

All other things being equal and done right it doesn't really matter. However, using *nix will ultimately be easier to deal with than windows so php is probably better.

PHP in a *nix environment also allows you to unleash the power of Apache server without paying a dime towards third party modules. Page redirection, retaining html extension for PHP and other techniques involving the use of Mod_rewrite require no additional investment in a Linux/Apache server unlike IIS.

Exactly. And you can do it all on a shared host. So why did you ask ;-)

i got confused last few days. so i posted it here to hear from other what their opinion