Ultimate Responsibility (UR) is Robert Kane's concept that we can be responsible for current actions, ones that are essentially determined (this can only be adequate determinism, of course) by our character and values, as long as we formed that character ourselves by earlier free actions that he calls Self-Forming Actions.
Self-Forming Actions (SFAs) are free actions in the distant past that contribute to our character and values. When we act out of habit today, we trace the Ultimate Responsibility (UR) for those actions back to those SFAs. Although current habitual actions may seem (adequately) determined, they are still self-determined and thus free.
Self-Determination is the idea of a positive freedom, a freedom for actions that we originate, actions that are up to us. "Up to us" (in Greek, ἐφ' ἡμῖν) was the phrase used by Aristotle and Epicurus for human freedom.
Such acts constitute the essence of Free Will. Self-Determination is one of Mortimer Adler's terms in his great compilation work The Idea of Freedom, along with Self-Perfection and Self-Realization.
Origination is the idea that new causal chains can begin with an agent, something that is not predetermined to happen by events prior to the agent's deliberation (between alternative possibilities) and decision. Origination accounts for human creativity.
Ted Honderich is "dismayed" because the truth of determinism requires that we give up "origination" with its promise of an open future. For him, limiting freedom to classical compatibilistvoluntarism means we are not the authors of our own actions.
They are not "up to us."
Kane's Ultimate Responsibility (UR) restores the case for self-determination and origination and makes our actions up to us.