Brightway2 can be used from the interactive python shell. IPython is a nicer python shell that adds shortcuts, shell commands, and a lot else.
Jupyter notebooks are the probably the best way to interact with Brightway2 (the Brightway2 examples are all Jupyter notebooks). These lab notebooks open incredible possibilities for interactive, reproducible, collaborative, and understandable science. Read more about the praise IPython has been getting, and see some awesome demos.
The activity browser is a native user interface currently in development.