The theory of distributions is considered now as the calculus of the modern epoch.
This sentence, which is currently in the Sobolev article, doesn't sound right to me. Certainly distributions are very important in some areas of partial differential equations and topological vector spaces etc. But they are not currently taught to undergraduates as the new standard way to do calculus.
Maybe this article should have a bit more summary of the main properties and characteristics of Sobolev spaces, although the article on that subject is quite detailed. The idea that a function can be half-differentiable, for example, is so novel that it could be mentioned in this article about the person Sobolev.
--Alan U. Kennington (talk) 16:15, 9 April 2015 (UTC)