.htm doesn't actually mean it was made by FrontPage.
I look at the source code and look for horribly twisted code.
That means it was either created by FrontPage, or a mental patient on a horrible acid trip.
Or both.
However I also detest .htm extensions. I would like it because it was a 3 letter extension (which is logical), but every time I see .htm I think the page was made 2 or so years ago.
It reminds me of when most of the pages I looked at were .htm, and web hosts often never used .html.
Then, as I was getting into HTML, the main "thing" came to be using .html.
So I've used html since...nearly ever, and it just looks weird to me to use anything else for .html.
Personally though, I use an extention that tells me what the file is. php for PHP (and I hate the php3 extension...go figure), jsp, asp, cgi, and pl (for non-cgi perl files), etc.
It would seem a bit confusing if your html file was actually a PHP file.
But that's just me, cause I'm weird like that.
Like I'm not a fan of RTF files, just because the .rtf extension makes me think of something that isn't a text file. I don't know what, just not text.
While we are on the subject, I also have great dislike for .jpeg. Dag nabbit, it's .jpg. Only markup languages should have 4 letter extensions if you ask me 😉
And only C/C++ should use the hackjob looking .h files.
And the next time I see a .z file, I may just snap.
Sick, isn't it?