If writers can write under a pseudonym why can't coders?
It all comes down to what you mean by anonymous/pseudonymous. Do you mean that a determined investigator/the government couldn't track you down? Or do you mean that a casual user doesn't know your real name? The latter is pretty easy. The former is almost certainly quite a bit harder (and more expensive) depending on jurisdiction--and may not even be possible if the government in particular is serious enough.