Originally, SE sites loaded MathJax from
http://cdn.mathjax.org/mathjax/latest/MathJax.js
which did not work over https protocol. Two months ago, SE implemented a hack-ish solution: detecting if the client uses https and replacing the link with
https://c328740.ssl.cf1.rackcdn.com/mathjax/latest/MathJax.js
See the announcement.
On March 17, MathJax Team (represented by Peter Krautzberger) issued a call for testing:
We have set up a copy of the MathJax CDN on Google Cloud Storage in the hopes of eventually migrating the CDN from Rackspace to GCS.
We'd appreciate it if you are able to try out this copy and report any issues.
The base url (both http and https) is
mathjax-cdn.storage.googleapis.com
So for example, http://mathjax-cdn.storage.googleapis.com/mathjax/latest/MathJax.js will give you the latest version of MathJax. All MathJax versions are available.
Out of the SE sites using MathJax, Math.SE was the first to switch to the new copy. This is a much cleaner solution, since the link is protocol-relative.
Most users never noticed the CDN switch: so far we had only two reports, including this one.
If MathJaX does not render, click the above link to MathJax.js. If you get a message saying We're sorry, but this service is not available in your country... well, at least you'll know why.
Users should be aware that the current setup is somewhat experimental.
