Currently I use either a StartUpItem or launch it manually. Apple has marked 'start up items' as deprecated and recommended launchd to be used instead. Has anyone looked into making aiccu use launchd properly on MacOS X? The relevant document at Apple documenting how an application should behave, with regards to launchd is: http://developer.apple.com/documentation/MacOSX/Conceptual/BPSystemStartup/Articles/LaunchOnDemandDaemons.html In the section "Special Dependencies", it notes: "Your daemon may wait for a kernel service to be available. To do this, you should first register for service change notification using the functions described in IOKitLib.h. This header is part of the I/O Kit Framework, which is further documented in I/O Kit Framework Reference. After registering for these notifications, you should check to see if the service is already available. By doing this after registering for notifications, you avoid waiting forever if the service becomes available between checking for availability and registering for the notification." I am going to see with the tun/tap developers whether they publish a node in the I/O registry, that aiccu could use if adapted.