Let’s start with a question! What is the first thing that user seek on your website. Answers can be different but i think it is the performance of your site. Here performance of your site include mostly website speed such as how fast the web pages load.
Here as we discussing about public CDN, those are a web service that hosts and deliver open source project used in web development that is use of jquery library, use of Node.js, Angular.js, use of bootstrap. Here we have to use a little code of that open source project but for that we must add the entire library and the use of this entirely large library slow down the performance of the website. Use of free public CDN allows to overcome that problem and we can use their services for free of cost.
Free of cost is not the only reason that you should use free public CDN. It provides performance as we discussed easier, because they are able to serve such files and resources from multiple geographic location.
It is very reliable and it ensure lighter cached probability and the best thing is that it provides the ease of use and maintenance to manage the website.
So, the list is here to use for your web development projects.