TCPDF error: Unsupported image type: com/image-2591334-10491780 Sitemap Safe Browser, included as a download link in the interface, is actually a standalone program that everyone can download and run. It consists of a version of the Firefox web browser running inside VirtualBox. The sandboxed environment ensures that attacks against the browser are blocked from reaching the operating system. The solution concentrates on one browser, products by other vendors allow the user to sandbox any program.