AZC has switched from WP-LaTeX to MathJax. There was no real problem with WP-LaTeX, but MathJax offered some improvements:

- Improved rendering
- Local installation: MathJax can be installed on your own webserver, so that you're no longer reliant on external services
- Easier typing of LaTeX: in WP-LaTeX, you have to type the word LaTeX after the first dollar sign, and in MathJax you don't

Here is a before-and-after image (you'll have to click on it to view full size to see the difference properly):

Unfortunately, there is a disadvantage to MathJax: it's slower than the WP-LaTeX rendering. Supposedly MathJax will get faster in the next release. There is another alternative: KaTeX. It's very fast, but supports pretty much none of the more advanced things like mathbb fonts, matrices, and various symbol that I use here. There was also a discussion on Math StackExchange about it.