Math Equations
It took about ten minutes to fork reveal.js to add equation support via MathJax ( http://mathjax.org ). You only drop the MathJax javascript into the header and it automatically renders anything like $y=x^2$ as an equation in any number of different formats. No live demo, but see: https://github.com/rreusser/reveal.js
Makes a lot of sense to me particularly since it's so simple, but there are a number of choices that would need to be smoothed out like which equation syntax to use, which display format to use, and how an editor like rvl.io would balance WYSIWYG with equations that need rendering.
Edit: Title changed to not specifically mention MathJax. There's a new library, KaTeX, which we will be using instead.
It’s now possible to easily display math formulas via the new Math block! Find out more: http://slides.com/news/math

Royi commented
@Owen,
You're using KaTeX which is not enough.Could you please allow using MathJaX which has many more features?
Thank You.

Anonymous commented
Another vote for inline equationsnot having them is a dealbreaker for me.

Daniel J. commented
Agreed with the commenters below. Is it possible to do inline equations? It seems like inline equations are possible with mathjax. Thanks!

Boaz Barak commented
Would be extremely useful for me if you could add inline math equations, without it it's much less useful for me.

Ricardo Chávez Cáliz commented
It would be very helpful if you can implement inline math. This could revolutionize the way scientists make slides

Steffen Schuldenzucker commented
inline math needed here as well. Otherwise, useless (and I'm stuck with beamer), unfortunately.

Andrew Neitzke commented
One more vote for supporting inline math, meaning math which appears in the middle of a line of text, not only in its own separate block.

Manu commented
Is it possible to render equation with katex in display style (\int and \sum are large)?

Bruno Beltran commented
Any updates on the ability to include math inline with KaTeX? It doesn't seem to work, unless I'm missing how to enable it.

tom commented
Is it possible to display inline math with this? It would appear that I can only use this to create a dedicated block for a math equation.

AdminOwen (Owner, Slides) commented
Thanks for the input, René. We are moving ahead with KaTeX and are getting close to finishing and releasing this feature.

René commented
I would definitely go for the light weight KaTeX implementation. At the moment it lacks support of \begin...\end environments (i.e. matrices), but it seems to be right around the corner. I think everything else that I need is there, and could live without matrices for now or work around it by positioning multiple equations to look like a matrix.
This feature would open the door to the scientific users and bring you way ahead of competing services like Prezi.

AdminOwen (Owner, Slides) commented
We started implementing this using MathJax but recently noticed that Khan Academy released an alternate and more lightweight library called KaTeX. We've got rough implementations using both libraries and KaTeX turned out to be significantly easier to integrate. There's a bit more info about the project here: http://khan.github.io/KaTeX/
We don't have any inhouse expertise about the different flavors of equations on the web so before we continue with KaTeX I'd love to get some input from all of you. Most importantly, does KaTeX have enough functionality to support your intended use? See https://github.com/Khan/KaTeX/wiki/FunctionSupportinKaTeX
Development has been very active so far and hopefully the range of supported functions will keep growing at a fast pace: https://github.com/Khan/KaTeX/issues

Saurabh Pradhan commented
I agree. It will helps a lot for scientific presentation.

Tim commented
agree with Ricky.