I distinctly recall stumbling upon a package which typeset derivatives nicely, and moreover automatically calculated some of the indices involved in partial differentiation. Unfortunately, I can't remember at all what this package is called.
Does anyone remember/know such a package?

coolpackage maybe? http://tex.stackexchange.com/q/54425/ – cgnieder Sep 27 '16 at 08:09esdiff,bropd, andphysicsare other packages I found in a quick search http://tex.stackexchange.com/search?q=derivative* – cgnieder Sep 27 '16 at 19:02