Existentialism is Humanism

Been reading Sartre a lot lately and one of the most interesting writings is actually his speech defending existentialism as not being a nihilistic approach. I personally think that this spech really did explain a lot about the views that the existentialists had.
'We mean that man first of all exists, encounters himself, surges up in the world – and defines himself afterwards. If man as the existentialist sees him is not definable, it is because to begin with he is nothing. He will not be anything until later, and then he will be what he makes of himself. Thus, there is no human nature, because there is no God to have a conception of it. Man simply is. Not that he is simply what he conceives himself to be, but he is what he wills, and as he conceives himself after already existing – as he wills to be after that leap towards existence. Man is nothing else but that which he makes of himself. That is the first principle of existentialism. '
The whole speech can be read here (link).