There are many people who do not believe in supernatural phenomena, and are convinced that we must always interpret all observations and experiences as NATURAL phenomena, governed by the laws of Nature. In other words, they subscribe to naturalism, as opposed to supernaturalism. They call themselves BRIGHTS.
This 'pomposity' (calling themselves Brights) was frowned upon by people who believe in supernaturalism. To accommodate the sentiments of such people, the Brights coined the equally flattering term SUPERS for them ('super' from 'supernatural'). So we have Brights and we have Supers.
The Brights have a less confrontationist approach than out-and-out atheists. I shall write about modern atheism in a separate blog.
The Brights Net is purely a net-based organisation. Anybody can become its member by registering (it is free of cost). Members get the monthly Bulletin by email. There are ~60000 members at present, spread all over the world. Out of these, ~60 have been given the epithet 'ENTHUSIASTIC BRIGHT'; these are people who have been particularly active and effective in spreading the message of naturalism.
Historically speaking, naturalism as a philosophy ensued as an aftermath of the work of Darwin and Freud. Its basic premise was that humans are governed by 'natural selection' (Darwin) and environment (Freud). It even gave rise to what is called 'naturalism art'. This limited idea of naturalism as a philosophy flourished from 1880 to ~1920.
With the ever-increasing influence of science, the present meaning of naturalism is far wider and deeper in scope. Anyway, to me it simply means rejection of supernatural causes. Natural phenomena can only have natural (as opposed to supernatural) explanations. The natural causes and effects are to be understood in terms of the known scientific laws of Nature (and nothing else).
I am an Enthusiastic Bright.
For knowing more about modern naturalism, the following URL may be a good place to start: http://nirmukta.net/Thread-Introduction-to-Naturalism