Web Application Inspector gives you information about what technologies are used on a website. Just click on the little icon that comes up in the search bar of your browser to see all of the applications that the Inspector recognizes.
It will tell you if it is built with Wordpress, Drupal, or Joomla for example.
It will tell you also if the site is using IIS, Apache, Nginx, for example as well.
The code makes all of it analysis locally, it doesn't make external calls. You can confirm this with TCPView or other tools if you are interested.
This is open source code that has been modified from the original work available at https://github.com/nqbao/chromesniffer. This modification includes an HTML icon which should show up on all websites even if the Inspector doesn't recognize anything else.
Extore is a team of professionals who are passionate about creating extensions for web browsers. This devotion also gives us opportunity to appreciate work of other people. We get inspired by useful, open source extensions made by developers all over the world. Our strong belief is that one should share helpful add-ons with others. That’s why we’d like to present you our ever-growing list of favourite extensions that have inspired us. Moreover, as you probably have already learned, sometimes struggling for the best brings an end to the good. Talking about add-ons it often turns out that an upgrade is worse then previous version. Also it can become really tricky to get back to the beloved version of your favourite extension. That’s why we’re going to make not only the latest, but all versions of our favourite (and we hope yours too) add-ons available for download. No more compromises, just stick to the version you really like!