Possible Duplicate:How can I close a terminal without killing the command running in it? If I open a terminal emulator, type firefox & and then close the terminal, the process it launched -Firefox- gets killed as it was its child.How can I prevent this behavior?
Launch independent process
process
Use the disown command.  In zsh you can also use &| to background and disown in a single operation.$ firefox &[1] 74773$ disown %1 # or disown %firefox$ firefox &| # zsh only; bash will report syntax error near unexpected token `|'