This website demonstrates DistilledODN making some simple changes to a website. You can visit the very same site in its original form and running via the ODN to see it making changes.
Click the button to go see the ODN in action:
You can visit an example page where a rel-canonical tag has been added. The original page is here and the ODN version here.
See an example where an X-Robots-Tag HTTP Header has been added. Check the headers of this page and then check the ODN version here.
It is easy to bulk change tag types; see where we have changed H4s for H3s. For example see this page and the ODN version here.
For each of a group of similar elements you can manipulate the content. Take a look at the list on this page and compare against the ODN version here.
DistilledODN can extract parts of a page to create dynamic content elsewhere on the page. See an example page here and the ODN version here.
You can add additional content to pages via DistilledODN. View the example page here and the ODN version here.
Of course, you can also add inline Javascript and CSS code to groups of pages. Take a look at this page and compare against the ODN version here.