The WebMatrix Extension Gallery is going offline and will no longer be directly available through the WebMatrix UI.
Are the Extensions gone?
No, we are making the entire Gallery available as a download - you can get all your favorite extensions here: http://aka.ms/wmgallerydownload
Why the change?
WebMatrix is going to move out of official product support soon and as part of that, the team is winding down various parts of the program
What other options are there?
Please take a look at Visual Studio Code - https://code.visualstudio.com/
The WebMatrix Team