The browser downloads the application from the YoctoHub and the JS library from the Yoctopuce web site
Icing on the cake if your browser supports it, the library files are transmitted as compressed files. Instead of downloading a 400Kb file, the browser automatically downloads the compressed version which is only 70Kb.
You can then use the library in your HTML page.
alert("Using Yoctopuce library " + YAPI.GetAPIVersion());
The http://www.yoctopuce.com/api/js address points on the most up-to-date version of the Yoctopuce library. But you can also use a specific version of the library. You must add the library version number at the end of the address (http://www.yoctopuce.com/api/js/XXXXX).
alert("Using first version of Yoctopuce library " + YAPI.GetAPIVersion());
In this way, you can start developing your application with the latest version. When your application is ready, you can freeze the library version that you want to use.
In short, as you can see, this "news" is not revolutionary, but it somewhat simplifies the developer's work. You don't have to download and install the library any more, you can simply reference it on you web application page to be able to use it.