MenuBarHider is a SIMBL plugin that loads into every Cocoa application you run and sets your Mac's Menu Bar to auto-hide itself, just like the Dock. When you move your mouse to the upper screen edge, it will reappear.

The plugin is tested on Mavericks. The deployment target is set to 10.5, so this should work on Leopard or newer. Note that I can't test the plugin on older OS X releases. Your feedback (in the form of an issue report) is appreciated.

This plugin will do nothing to Carbon-based applications, since SIMBL will only inject code into Cocoa applications. I haven't seen a Carbon application in a long time, though.

To install this plugin, either clone the git repository and use XCode to build the bundle, or get a precompiled bundle from the downloads section on GitHub. Then put the bundle into "~/Library/Application Support/SIMBL/Plugins". If you had installed EasySIMBL before, just restart your applications. If you don't have EasySIMBL on your machine yet, get it from https://github.com/norio-nomura/EasySIMBL and follow the instructions there to install.

Note that I recommend to use EasySIMBL, since it includes a workaround for sandboxed applications. Regarding Google Chrome, please see norio-nomura/EasySIMBL#12.