git-annex.app

For easy installation, use the prebuilt app bundle.

To run the git-annex assistant, just install the app, look for the icon, and start it up.

To use git-annex at the command line, you can add git-annex.app/Contents/MacOS to your PATH

Alternatively, from the command line you can run git-annex.app/Contents/MacOS/runshell, which makes your shell use all the programs bundled inside the app, including not just git-annex, but git, and several more. Handy if you don't otherwise have git installed.

autobuilds

Joey autobuilds the app for 10.10 Yosemite (also reported to work on 10.9 Mavericks). Thanks to Kevin McKenzie for hosting the autobuilder.

using Homebrew

git-annex is now available in Homebrew!

using MacPorts

git-annex is not available in MacPorts, but can be built from source using MacPorts tools. See MacPorts.

building it yourself

See porting.