Maple and Mathematica are not open, and it's important that not only the resources be open-source, but also the underlying technology stack, because we're trying to not only teach students mathematics but the most engaged students need to "look under the hood" and learn how the technology works.

So we do support SageMath for more complicated answer validation. This depends on the public SageMath cell servers, which provides cloud-hosted SageMath and enables things like \sage{derivative(x*x,x)}. It's also more performant to rely on JavaScript.

For developmental math, answer validation is somewhat harder than for calculus, because often you want to distinguish between say (x+1)^2 and x^2 + 2x + 1.

We run workshops on how to use Ximera. The next one is at UFlorida in October. If you're interested, there is some travel support available. Contact us at ximera@math.osu.edu