I am currently in graduate school and I work on modeling. The systems I model rely heavily on stiff ODE solvers (i.e. ode15s in MATLAB) and non-linear solvers as well for solving non-linear reaction and diffusion equations. So far I have typically used MATLAB for my work, but I feel like this will limit me when I apply for a job, since companies may not be willing to shell out 1000's in licensing fees if they can just use open source products. So, I want to learn another language that will be useful for my modeling work. I have considered C using the GSL, but I want to make sure that what I invest time in will be the best choice. What do you guys recommend I should pick? It's not really necessary to have solvers in place. I could write my own if need be. What's really important is being able to manipulate matrices as easily as it's done in MATLAB, and that the language is powerful with a learning curve that's not too bad. I have a fair amount of experience already in C. Thanks.