Can SSI be done without renaming the file to .shtml?

yes, simply specify that you want the extension .html (for example) instead of shtml to be parsed as ssi.

Howeverf, that will slow down the server, since every .html pages will be parsed.

The change has to be done in your httpd.conf or srm.conf file.

Alternately, you could specify such parsing for a single domain in a .htaccess file, pleaced in the root directory of that domain. It will still tend to slow down retrieval of pages on that site.

Dang, that's what I was going to say (.htaccess)! :) I was in class though and I don't trust the school people with my passwords.

The line for making other extensions parsed is:
AddHandler server-parsed .html

replace .html with whatever extension you wish.

Of course, most web hosts discourage enabling SSI without discrimination, due to the overload it puts on the server.

p.s: I have SSI mass enabled on all html files as well :)

Personally (as a web host) it is not the overload on the server that concerns me, but the fact that pages tends to ahve a .5 longer delay before loading (because it is being parsed). I find this to be quite slow, when you know that you can have a relatively more complex php script doing much more taking .02 seconds to load :)

Anyway, in my opinion, renaming your file .shtml isn't a real big deal and it will make your site faster.

The problem with renaming it to .shtml is the search engine will not pick up if you already submit it

hmmm yah true.

there are other possibilities than simply put all the html to SSI, like redirecting any missing .html to an equivalent .shtml for example. That would only generate due system load (well a bit more than usual, but less that broad ssi parsing).

I believe that could be done with a .htaccess file fairly easill. Or a script as the .404 error.

Anyway, I still don't think that puting all the .html to .shtml is a good idea... unless it is for 1 site only and that the site does not require an excellent speed.

You are correct about the search engines; hoever, you really shouldn't be concerned about that considering you need to resubmit (most of the time) to the search engines every month or so for a fairly effective campaign.

While your .htaccess'ing things, could you throw in a redirect line that directs file.html to file.shtml (I know you can do this), *and* have that work for the s-engines? Not sure this would help or not, but might be worth a shot?