Are you using RK-Opt in research work to be published? If so, please include explicit mention of our work in your publication. We suggest language such as this:
“To solve problem (17), we used RK-Opt, a package for optimization of Runge-Kutta methods ,”
with the following entry in your bibliography:
 RK-Opt: Software for the design of Runge-Kutta methods, version 0.2. DI Ketcheson, M Parsani, and AJ Ahmadia. http://numerics.kaust.edu.sa/RK-opt, April 2013.
as well as one or more of those below. Specifically, if you use the RK-coeff-opt package to optimize SSP coefficients, please reference . If you use the RK-coeff-opt package to develop low-storage methods, please reference . If you use the RK-coeff-opt package to optimize for accuracy, and/or enforce a given stability function, please reference . If you use the RK-coeff-opt package to develop general linear methods, please reference . If you use the polyopt package, please reference . If you use the am_rad-opt package, please reference .
 Highly Efficient Strong Stability Preserving Runge-Kutta Methods with Low-Storage Implementations. David I. Ketcheson, SIAM Journal on Scientific Computing, 30(4):2113-2136 (2008)
 Runge–Kutta methods with minimum storage implementations. David I. Ketcheson, Journal of Computational Physics, 229(5):1763-1773 (2010)
 Optimized explicit Runge-Kutta schemes for the spectral difference method applied to wave propagation problems. Matteo Parsani, David I. Ketcheson, and W Deconinck, SIAM Journal on Scientific Computing. In press. Pre-print available at http://arxiv.org/abs/1207.5830. (2013)
 Optimal stability polynomials for numerical integration of initial value problems. David I. Ketcheson and Aron J. Ahmadia, Communications in Applied Mathematics and Computational Science, 7(2):247-271 (2012)
 Computation of optimal monotonicity preserving general linear methods. David I. Ketcheson, Mathematics of Computation, 78(267):1497-1513 (2009)
 Strong Stability Preserving Two-step Runge–Kutta Methods. DI Ketcheson, S Gottlieb, CB Macdonald, SIAM Journal on Numerical Analysis, 2011;49(6):2618 (2011).
Also, please do let us know if you are using this software so we can add your work to our Applications section.