A 3D graphical interface for building, simulating and optimizing Markov kinetic models in response to user defined time dependent stimuli. Models can be represented as either states and connecting transitions or interacting allosteric elements (see http://dx.doi.org/10.1085/jgp.201411183). Model parameters can be optimized by fitting model responses to user data. Optional user defined constraint equations for model parameters are parsed with EigenLab (https://github.com/marcel-goldschen-ohm/EigenLab). Convenient simulation and summarization across 2-dimensional sets of stimulus conditions makes constructing stimulus-response curves incredibly simple. For ion channels, this is useful for simulating dose-response or current-voltage curves both with and without a secondary stimulus (e.g. some drug). A series of video tutorials are available at https://www.youtube.com/watch?v=7I2XPkdOvCg&list=PL-J_lULjiFsCPL2pkz8_tFe_aJ4Fc8a8k&index=1.
I have used numerous software packages, both commercial and free, for simulating and fitting receptor gating schemes and this is, by far, my favorite. Its incredibly flexible in terms of the number of states, ligands, conditions and experiments one can run and the ability to global fit all these types of data is amazing. It only gets better with each iteration and the developer is fantastic at helping or supporting specific issues as they crop off. If you are interested in simulating or fitting receptor schemes, this is definitely a program you should try!