Sage is a python-based mathematics software that integrates a wide range of mathematics software into a single python interface.
Calling sage from the terminal (which is how you call it) creates a CLI version of sage (the program's default) from which you can then call the sage notebook by typing,
notebook(). The sage notebook is a web browser-based version of sage. I am running i386 12.10 if it helps.
When I run
sage notebook() from the terminal I receive the error:
bash: syntax error near unexpected token `('