So, if I turn on my computer and open Firefox and go to Math Stackexchange's website, my Firefox freezes for 10 seconds. In fact, today, I clicked on the link to Math Stackexchange, and immediately minimized my browser and tried to open up a PDF. But, I couldn't do that either. So, my computer is basically completely useless for 10 seconds.
Compared to all the benefits of MathJax, I agree this is a minor thing. But, no computer program should act this way. Can't something be done so that while it is getting started, or doing whatever it is doing, I can still run my computer? I can't think of any other program I use that freezes my entire computer for 10 seconds, or even close to it.