Is there a native domain mapping for WP?

It seems like the "standard" domain mapping plugin used by most in the WP community is this plugin:
http://wordpress.org/extend/plugins/wordpress-mu-domain-mapping/

It actually looks identical to the WPMUDev domain mapping plugin. Are these actually the same or what is the difference? Is this functionality built into WP already without the need of a plugin at all? Thanks for shedding any light on this.