Michelle Weiner Davis is a real bulldog for marriage. (www.divorcebusting.com)
Michelle focuses on what is called Solution Oriented Therapy. In other words, rather than focusing primarily on what has gone wrong in the past in an individual's life or marriage, she focuses on "What can we do right going forward?"
She has written various books on saving marriages. There is a forum on her website.
Michelle also offers Divorce Busting Coaches. These are coaches who have been trained in her methods to help a person, who wants to save their marriage even when a spouse isn't willing, to devise strategies that have a high chance of success. I never used this service, but I probably would have tried it if Sharon had gone farther towards divorce before she reconciled with me.