The morphology files are automatically generated by a 3d reconstruction program called neurolucida. NEURON is an ancient program, written in 1983, using a custo

The morphology files are automatically generated by a 3d reconstruction program called neurolucida. NEURON is an ancient program, written in 1983, using a custom parser for the ad-hoc language literally called hoc. It has a hardcoded limit in the number of lines a function can have (hence you have to split func1(), func2() etc) and a gazillion bugs. It uses a modified kinetic equation solver which compiles those .mod files to to a DLL that NEURON then uses to run. It uses some GUI library called InterViews from god knows where. It's generally a rather bad program nowadays, but written by the guy who invented a faster Crank-nicholson method to integrate the cable equations (Hines). Despite a few alternatives existing, NEURON is still the most popular because there are a lot of ion mechanism kinetic modules (the mod files) that you can download and reuse from previously published models, which have been hand-tuned to be quasi-realistic. NEURON is supposed to be used by neurophysiologists, not by programmers. I think a mass open source campaign to replace NEURON and ModelDB with something more modern, and clean up and convert every published model would be worth the effort. There are quite a few alternative programs (GENESIS, Neuroconstruct etc) that are either incomplete or abandoned because of lack of funding/interest.