What is Existentialism?

We will begin with a general discussion over Existentialism: What is it? Which philosophers were actually Existentialist? Is Existentialism still relevant today? Does "existence precede essence"? And what does that even mean?

For those who would like to read up on the subject beforehand, here is a link to the Stanford Encyclopedia of Philosophy's entry for Existentialism: http://plato.stanford.edu/entries/existentialism/

At the end we will decide which text is going to be discussed at our next meetup. Currently, the organizer is leaning towards Kierkegaard's Fear and Trembling or The Present Age but will offer other suggestions (and he's always open to your's).