How definitions are stored

When you use the Web interface of Mathics, a browser session is created. Cookies have to be enabled to allow this. Your session holds a key which is used to access your definitions that are stored in a database on the server. As long as you don't clear the cookies in your browser, your definitions will remain even when you close and re-open the browser.

This implies that you should not store sensitive, private information in Mathics variables when using the online Web interface, of course. In addition to their values being stored in a database on the server, your queries might be saved for debugging purposes. However, the fact that they are transmitted over plain HTTP should make you aware that you should not transmit any sensitive information. When you want to do calculations with that kind of stuff, simply install Mathics locally!

When you use Mathics on a public terminal, use the command Quit[] to erase all your definitions and close the browser window.