Convert NON-CMS site to Sitefinity 4

My company has a public facing, non-cms managed web site that we want to convert to use Sitefinity, but I am not finding via searches or otherwise any strategies/tactics that people use to do so. We need the Sitefinity managed site's URLs to match the original, and we need to do it in stages. Can this be done? If so, how?

Do you need to preserve the format of the urls, or simply ensure that they are not lost?

Sitefinity allows you to specify alternate urls to each individual page and content item, which can certainly match your existing pages when they replace them.

Alternatively, you can use rewrite rules, which is especially helpful (and recommended) if your old urls use extensions such as .php or .aspx because Sitefinity uses no extensions in the url for better SEO.

A combination of the two (rewriting urls to remove the extensions then keeping the old urls as alternates) should probably allow you to upgrade your site without losing any existing SEO you've accumulated.

You can also convert your site in sections; the file-based html files, images, and folders can serve from the file system simultaneously along side the dynamic Sitefinity CMS pages.

I hope this is helpful!

Based on conversations with my boss, we would "prefer" the format not to change, but might be able to live with making sure they are not lost. It sounds like the URL rewriter may work, at least once we have pages converted, but the problem I'm having is PRIOR to the conversion of a particular page to Sitefinity. How to show a .aspx page that is NOT under Sitefinity's direct control.

This is a helpful start - are you aware of any documents or web sites that describe the "process" to follow when converting a web site to use Sitefinity over a period of time? Any more information about "process" would be very helpful!

You mention the file-based stuff - we really don't have more than a couple straight html pages - most are .aspx pages along with code behind and a fair amount of javascript coding. For the life of me, I haven't been able to find out how to continue to use the .aspx pages while doing the conversion. Every "conversion" link ends up being to convert from one release of SF to another.