New version of OpenGlasses. Why 2.0? The new version breaks API compatibility and adds new features. More info on the wiki.
The Mod is called OpenGlasses and is an extension to OpenComputers. It is analogous to glasses from the OpenPeripherals add-on for ComputerCraft, but adds a few more nifty features.
OpenGlasses is a mod which adds Augmented Reality features to Minecraft. You can render objects, like shapes and text both in the world and on the players HUD, only visible to those with the Open Glasses on (think Google Glass, but in blocky form).
note for Optifine users: rebind the Optifine Zoom key or OpenGlasses overlay key if you use both mods