MathJax v2.6 focuses on completing the CommonHTML output and improving accessibility of MathJax. It also includes more than 30 important bug fixes.

For more information checkout

• https://github.com/mathjax/MathJax/issues?q=milestone%3A%22MathJax+v2.6%22
• https://docs.mathjax.org/en/latest/whats-new-2.6.html
• https://www.mathjax.org/mathjax-v2-6-beta-now-available/