The J executables j.exe and j.dll are installed in the main J directory, for example, c:\j406.
The following system subdirectories are created by the J installation:
Main libraries and utilities
Packages (e.g. Stats, Printing)
Class definitions (e.g. Grid, Plot)
Various system utilities
In addition, two other subdirectories are created when J is installed:
Subdirectory Addons is created when one of the J Addons is installed.