Matlab, the SAS of academia and certain engineering fields.
I would never use it for producing software meant for distribution, but people mainly hate on it because it's 'cool', without realising that it excels at what it does. I fucking love matlab.
Diffeq are one of those things that Julia is a particularly good choice for that benefits strongly from its types and what not. Give it a shot if you do a lot of this.
Julia syntax resembles matlab more than python or R.