The book covers a useful analysis of the roots of socialism, and then chronicles how it diverged into communism on the one hand and more moderate social democratic parties on the other hand. To illustrate this, there is an interesting comparison between communists and social democrats in action, with a chapter dedicated to how Cuba and Sweden used the respective systems in their public policy, often allowing it to cross fertilise with cultural mores (especially true of Sweden), and a discussion of how the Cuban system may not survive Castro's death, being as it is largely based on Castro's personal charisma. By contrast, the Swedish system has much better prospects for long term survival, although it did struggle during the neo-liberal 1980s.
There is also an interesting look at how "green" policies have influenced recent socialist thinking, explaining how this was a significant challenge to traditional socialism and communism, both of which took unlimited growth and industrial activity for granted. By contrast, the greens argued that the emphasis should be on managed growth, and that if this growth threatened the planet, growth should be stopped. Interestingly the greens believed that this was simply an extension of the socialist belief that whilst traditional socialists should care for society's members now, they also had a duty to look after the planet and thus take care of society's future members.
The author also examines how socialism has fragmented, with increasing attention being paid to gender and ethnicity, and less to class amongst more recent writers, a considerable break with tradition. One refreshing feature of the book is the author's honesty, and far from being a partisan rant, the author freely admits that his/her ideology has its flaws and that amending them is not going to be easy. All in all, a good introduction to the semi-interested reader, but more interested readers in the subject of socialism may need to read a more "deep" text.