I propose that a future version of Firefox have an optional feature that runs all Firefox code, cookies, file downloads and sensitive FF files in an emulation mode within a sandboxed environment. For many years I ran Firefox and other web browsers from inside a software container app called 'Sandboxie'. As a security environment, a sandbox app prevents any website or links from auto-executing malware scripts that can cause changes to the system software, or inserting malicious code into the root drive and boot-up files. The current version of Sandboxie Plus allows many different applications to run in its sandbox, but its current development is owned by an individual, not a software company. Can Firefox be improved to create it's own security sandbox when it is running?