Beamer lets you send Video from non-Airplay Macs to AppleTVs
http://www.macworld.com/article/2023617/mac-gems-beamer-streams-video-from-older-macs-to-apple-tv.html
QuickRes for the new MacBook w/ Retina Displays – lets you set the resolution to what ever you need it to be, not just the apple provided resolutions
I’m thinking in particular of the MediaScapes and large LCDs – 1920×768 is not an offered resolution on some Macs.
http://www.macworld.com/article/2012693/mac-gems-quickres-helps-you-get-the-most-out-of-retina-displays.html
There is a version of this software for non-retina Macs as well.
http://www.macworld.com/article/2013295/display-menu-brings-back-os-xs-displays-menu.html