''See'' is a software framework for simulation of biologically detailed and artificial neural networks and systems. It includes an general purpose scripting language, based on Scheme, which also can be used interactively, while the basic framework is written in C++. Models can be built on the Scheme level from ''simulation objects'', each representing a population of neurons, a projection, etc. The simulator provides a flexible and efficient protocol for data transfer between such objects. See contains a user interface to the parallelized, platform independent, library SPLIT intended for biologically detailed modeling of large-scale networks and is easy to extend with new user code, both on the C++ and Scheme levels.