Stupid simple spawn, allows for supervisor to be run and prevents it from being restarted each time.

grunt_supervisor.js

var proc = null;
grunt.registerTask('supervisor', function(){
	if(!proc){
		proc = grunt.util.spawn(this.options());
	}
});


grunt.initConfig({
	supervisor : {
		options: { 
			cmd : 'supervisor', 
			args : ['src/server/app.js']
		}
	}
});