Routine Poutine26,034 Points
Why is this course being retired on June 19? Is it obsolete?
Brendan WhitingFront End Web Development Techdegree Graduate 84,600 Points
What you're probably looking for is Working with the Fetch API. This is the modern way of doing AJAX requests. It's now native to most modern browsers. It's promise-based rather than callback-based (you can learn more about that here).
Another option is to use axios. It's not native to the browser like fetch is now, so you'll have to import the library, but some people prefer the API, and also you can use axios on the node server side as well, so it's nice to have consistency if you have a full stack JS project.
It might still be worth your while to learn a bit about the older way of doing AJAX requests. You'll probably hear people referring to this way of doing things and there is legacy code out there.
Jonathan GrieveTreehouse Moderator 85,422 Points
It looks like the course has been discreetly updated with only the first 2 sections of the retired course updated in the new course. I'm guessing the other 2 will one day be added in a new course. It uses the old graphics and the previous backdrop for the Portland studio.
Kevin Gates14,748 Points
They normally only retire courses if they have uploaded or will upload soon new versions of the course.
Modern technology stacks are evolving regularly so it's best to get the latest information.