No other headless browser out there besides PhantomJS while the latter is a dead-end with Protractor.
You can try docker-selenium or, if you don't like Docker you can do it yourself with ubuntu-headless sample. Both solutions provide Chrome & Firefox by using Xvfb even though there is no real DISPLAY.
UPDATE 2 Seems to be possible to run Xvfb in OSX: http://xquartz.macosforge.org/landing/
UPDATE 1 Mac OSX selenium headless solution:
Enable multi-user remote desktop access to OSX machine
So can test selenium headless on mac. Not headless really but as another user so it doesn't interfere with your current user display.
To do this you need kickstart: http://support.apple.com/en-us/HT201710
Begin using the kickstart utility
sudo /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart -restart -agent
Activate Remote Desktop Sharing, enable access privileges for all users and restart ARD Agent:
sudo /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart -activate -configure -access -on -restart -agent -privs -all
Apple Remote Desktop 3.2 or later only
Allow access for all users and give all users full access
sudo /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart -configure -allowAccessFor -allUsers -privs -all
Kickstart help command
sudo /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart -help
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