Apple has released iMac Update for Mac OS X.

The update is for iMacs running Mac OS X 10.1.5 build 5T91. The build number is listed in the About this Mac dialogue in the Apple menu.

The 2.5MB download includes enhancements to installation of third-party applications, as well as Networking Update, that improves network and Internet access after restarting an iMac, or waking it from sleep.