I am about to launch a new website (unfortunately, an NDA keeps me from disclosing any details), and I came across the issue of which file extension to use. The URL-structure is created with URL-rewrites, the files generated include the proper mine-type, so I am basically free to use any file extension I like.
Now, the question is, which file extension would be best from an SEO point of view. Ie. no extension (à la Wikipedia), or using .htm (Windows/Dos-World) or even .html.
I came across only one article that was at least marginably sound. In that article, it was stated, that anything that helps the spiders detect the file-type properly can only improve indexing. So, they suggested to use .htm or .html, but gave no thumbs up or down on using no file extension at all.
What is the concensus of this forum ?

TOM