Simple inheritance with Object.create() and a factory function

gistfile1.txt

var makeObject = function(prototype, properties) {
  var newObject = Object.create(prototype || null) // If no prototype is set, just create a regular object literal (which inherits from null)
  for ( var property in properties ) {
    if ( properties.hasOwnProperty(property) ) {
      newObject[property] = properties[property]
    }
  }
  return newObject
}

var person = makeObject(null, {
  sayHello:function(){console.log('Hi there')}
})

var man = makeObject(person, {
  sex: 'male'
})

var mike = makeObject(man, {
  firstName: 'Mike',
  lastName: 'MacCana'
})

Indeed looks very nice. How do you handle computed property values and internal instance properties? You probably know my (related) approach, which is a bit more library code, but not much:
https://github.com/rauschma/proto-js