Dear Colleagues, CARLsim is an efficient, easy-to-use, GPU-accelerated library for simulating spiking neural network (SNN) models with a high degree of biological detail. Originating in 2009, CARLsim is now on its 6th major release. CARLsim supports CPU and GPU simulations ranging from small networks to networks with hundreds of thousands of neurons with millions of synaptic connections. It is supported on Linux, MacOS, and Windows. The software framework is open-source and freely available. More information can be found at: https://sites.socsci.uci.edu/~jkrichma/CARLsim/ This survey is intended for anyone who has used the CARLsim spiking neural network simulator, or who might like to use CARLsim in the future. It will help the CARLsim team develop future versions on the software framework. We appreciate your input and feedback. Please use this link to take our survey. https://forms.gle/GyVsuuey4mDB3bsB7 Thank you, Jeff Krichmar Department of Cognitive Sciences 2328 Social & Behavioral Sciences Gateway University of California, Irvine Irvine, CA 92697-5100 jkrichma@uci.edu http://www.socsci.uci.edu/~jkrichma