The ./configure script is the root of the configuration data tree. All basic configuration values should be defined by running this script. The data flows out to two primary places: ./config.rb and vm/gen/config.h. The data in config.rb can be loaded to access configuration values in e.g. rake tasks. The data in vm/gen/config.h is used to set the fundamental constants in the VM. All other configuration data is derived from these two locations. For example, lib/rbconfig.rb values are derived from the basic path constants defined via config.h.