On this web site, I try to show examples rather than how things work theorically, which a lot of sites you can easily find. Most of articles wrote by myself, some of them are partially from other site which I think they have done very good job, I just improved it a bit more, or I just totaly agree they have done job better than I can do, I put their link in my particles to credit their their hardwork. Anyone, if you don't want your link in my article, let me know, I'll remove it.
As I said, It's my site for sharing, so their is no copyright on all articles, except some GPL explicitly cited in the package, well, it's also free. Would be good you can give me some credit when you copy, cite, refer to others, thanks!