This is how it is along with other so many URLs, it's not a wordpress website. Do you think the sitemap is auto generated? or automated? Automated in the sense the plugins/scripts are updating the sitemap automatically with the server logs files as a new web page in the site is going live and getting some traffic? That's how these plugins work right?
When you say "along with other so many URLs" do you mean that you snipped the rest of the URLs to post it here? Or do you mean that you are getting a sitemap for each page on the site? Most sitemaps are generated by use of an installed script and automatically update when a new page is added. They don't normally carry the script in the header, this one looks like it was not correctly installed, if I had to guess. Depending on the type of site it is, there are a variety of scripts you can use. I would think about uninstalling the script that is generating that as output and installing a new one. Plugins generally refers to scripts added to WordPress, since this isn't a wordpress site, it is more likely a script, but you didn't say what kind of site it is. A defective sitemap would be giving you errors in your Webmaster Tools accounts.
do you mean that you snipped the rest of the URLs to post it here?
Yes, there are 1800 URLs in it, I just cut them all after the homepage URL and added the closing URLSET tag at the end to make it a one URL XML sitemap so that I could post it here.
Most sitemaps are generated by use of an installed script and automatically update when a new page is added
That's what I was trying find here. This is a new site which came through a recent acquisition. So, I cannot get to connect to the web dev team to see if the XML sitemap on the site is automated. I am checking it on my own to find if it's automated(the script is updating it regularly) or generated once(and never updated after that)
They don't normally carry the script in the header, this one looks like it was not correctly installed, if I had to guess. A defective sitemap would be giving you errors in your Webmaster Tools accounts.
I checked it with almost all the XML validators, XML sitemap checkers online but the result was OK. So, when I move to the XML path at example.com/sitemap.xml and click on the page and save it to my desktop as XML file, the script is not there.
It's a .NET site on the IIS server.
So, can I assume that this sitemap is auto updated because there is a visible script at the top and no online tools find it to be invalid?