Is there any support for rendering/displaying mathematical formulas under iOS? I'm assuming there's nothing built-in to the OS itself, so a solution that is free-as-in-beer and won't cause my app to get rejected are priorities.
Is anyone aware of such a library?
There is no built-in support for this in iOS. The general answer for questions regarding custom text layout is to use a UIWebView, which gives you powerful control over the layout and rendering of text and symbols via HTML and CSS. You might want to explore that as an option, if there aren't any ready-made solutions more suited to your needs.
I had a similar requirement for a project at one point, and I was planning on using Texify to either render equations in-app using a
UIWebVIew
or pre-render forumulae offline and then include the renderings (as static images) in the app. I ended up doing neither because the requirement changed.You might want to know that there is already an TeX editor vor iOS available, called TeX Touch. It submits the .tex files to a server, which returns the rendered files. Exchange is done via Dropbox: http://www.vancapy.com/textouch/