Math equations

I have a series of related questions.

What is the best platform to build accessible math equations: Word, Google Docs, or Canvas?

I've found the MathType add-in for Word and Google.  Most places say this is accessible, but I've found a few that say this isn't good enough.

One site suggested MathHML.  Is this better?

How does one build accessible math equations in Canvas? 

Thank you for your help with this.