(see ftp://ftp.sas.com/pub/neural/FAQ5.html for a more complete list)

Neural Network Toolkits:

   The Stuttgart Neural Network Simulator supports a number of different
   kinds of neural networks.  It's build on a C kernel, and has an X-Windows
   GUI interface to "create, manipulate and visualize nets in various ways."
   You can find out more from http://www-ra.informatik/uni-tuebingen.de/SNNS 

Neural Systems (Biological Simulation):

   BIOSIM is a biologically-oriented neural network simulator.  It
   implements four neuron models: a simple model only switching ion
   channels on and off, the original Hodgkin-Huxley model, the SWIM model
   (a modified HH model) and the Golowasch-Buchholz model (the most
   enhanced model). Dendrites consist of a chain of segments without
   bifurcation.  It is in the public domain and runs on Unix workstations
   (a less-powerful PC version is also available). BIOSIM includes a
   graphical user interface and was designed for research and teaching.
   It is available by anonymous ftp from

      ftp.uni-kl.de:/pub/bio/neurobio [131.246.9.95]

   For more information, write to Stefan Bergdoll <bergdoll@zxa.basf-ag.de>.

    GENESIS (short for GEneral NEural SImulation System) is a general
    purpose simulation platform which was developed to support the
    simulation of neural systems ranging from complex models of single
    neurons to simulations of large networks made up of more abstract
    neuronal components. GENESIS has provided the basis for laboratory
    courses in neural simulation at both Caltech and the Marine
    Biological Laboratory in Woods Hole, MA, as well as many other
    institutions. Most current GENESIS applications involve realistic
    simulations of biological neural systems. Although the software
    can also model more abstract networks, other simulators are more
    suitable for backpropagation and similar connectionist modeling.
    The homepage is located at:    http://www.genesis-sim.org/GENESIS/