1. Download the page and required code to the browser
2. Retrieve help files, manuals, and images
3. Retrieve sample vector and/or insert sequences
No user data is transferred out of the browser across your firewall to NEB's servers. This can be verified by disabling your internet connection to the browser after the page has loaded. While you will not have the convenience of getting vector sequences, the rest of the application should work fine and produce the desired primers.
NEBuilder is not open-sourced at this time, nor is it available in a standalone desktop version.