Hmm. Try doing a search on cpan for "daemon". Either run cpan (perl -MCPAN -eshell), and use the i command (i /daemon/), or go to search.cpan.org and use the search box in the mid-left. Or, for bonus points, /msg yourself [cpan://daemon].

Any of the above will point you at Proc::Daemon, which will do what you want.