What language is more suitable for the development of WeChat applets?

Is there a choice? Isn't it JavaScript Although wxs code can be inserted into wxml, it is actually JavaScript. The applet is based on the browser kernel (but different from the browser), so the program code can only be based on the browser scripting language, namely JavaScript.

If you are talking about background programs, there is no limit. You can use whatever you like, as long as you can receive the connection request of the applet and return the data in the format required by the applet. Of course, WeChat officially recommends nodejs and php. However, this is not directly related to the applet itself, because the background program for developing ordinary apps is exactly the same.