I wrote:
It is the purpose of this expository note to provide a self-contained, elementary and brief development of the fact that the exponentiable topological spaces are precisely the core-compact spaces. The only prerequisite is a basic knowledge of topology (continuous functions, product topology and compactness). We hope that teachers and students of topology will find this useful. As far as we know, there is no such development available in the literature. Although there are one or two embellishments, our methods are certainly not original.
------------------------------------------------------------------- http://www.dcs.st-and.ac.uk/~mhe/papers/exponentiablespaces.ps
It turns out, as Fred Linton kindly let me know just after I posted this, that Eilenberg developed such an account to general function spaces in topology. Yesterday I got a copy of Eilenberg's manuscript (in the literal sense of manuscript) that Fred Linton sent me, which I read with pleasure. Apparently this will be eventually published. It was written around 1985. So, after all, there is (going to be) such a development available in the literature. The methods that both papers use are the same, and are due to Fox, Arens, Dugundji, Day and Kelly, Scott, and Isbell (although we combine them in different ways). These references and most of these methods are discussed in a paper on function spaces published by Isbell in 1985. Martin