I had thought before posting that most people at Less Wrong were utilitarians.

Some amateur etymology, for those enamored of distinctions:

Most people here seem to be consequentialists, and consequentialism is merely the view that an action's goodness is defined by its outcome. Most are also 'utilitarians', seemingly meaning that they believe expected utility maximization is the correct metric for ranking outcomes, where 'utility' refers simply to the output of an agent's utility function. Probably most are also 'altruists', where altruism is the view that doing good things for others is good for oneself.

This is a departure from how the terms are used in the ethical literature. There, 'utilitarianism' tends to refer to an agent-neutral consequentialist moral theory; that is, my survival doesn't matter any more than yours. Also, 'altruism' in ethics refers to a theory that looks just like utilitarianism but discounts the agent entirely; think Christian self-sacrifice.

Our use of the term 'utility' has its roots in game theory, decision theory, and economics; our 'utilitarianism' seems to be an offshoot of that. Our use of the term 'altruism' seems to come from anthropology by way of evolutionary psychology.