There is also Gaianism and Materialistic Pantheism, Secular Naturalism, and non-denominational or non-secular Humanism (which allows anyone from any spirituality to be a part of it)... These all share a pretty similar outlook to the one described above.
One of the reasons people don't consider Buddhism a religion. You can be an atheist and a Buddhist or a Christian and a Buddhist or a Freethinker and a Buddhist. Buddha doesn't care. Which is why I have always been attracted to buddhism.