#Wikipedia has potentially articles on any subject. When it is about other countries, MediaWiki supports fonts when needed. When it includes mathematics, there is another need; the need to display formula properly. Mathjax has as its slogan: "beautiful math in all browsers" and it does do a great job.
The one thing that was holding back adoption of MathJax was its lack of support of other languages.
Now that the community of localisers at translatewiki.net has adopted MathJax it is a different story. The lack of a localisation can be fixed in the time honoured way; you can do it. There is not only support for the localisation in potentially 300+ languages, there is also strong internationalisation support available when needed.
When your Open Source software needs an international audience, consider translatewiki.