You probably meant to go to localhost:8000, and ended up here by accident.
In computer networking, localhost is a hostname that refers back to the same computer. The number following the colon is a port number. The port number 8000 is commonly used for web development frameworks such as Django, Ruby on Rails and AngularJS.
Our best guess is that just like us, you ended up here as you were working on web development with these - or other platforms - and your browser auto-completed your request, making it a request to localhost8000.com instead :)