I still don't know, nor can be bothered working out various different unnecessary markup languages, and I program. God forbid anyone whose talents lie elsewhere tries to contribute.
It's okay, most likely some overzealous editor will simply delete whatever that person contributes anyway. Contributing to Wikipedia as a non-editor is a massive waste of time since even minor submissions get killed quickly and quickly turn into massive fights over notoriety and content.
Do you mean "contributing to Wikipedia as someone without a user account"? I just started doing Wikipedia edits, having first set up a Wikipedia account, when I declared a vacation from Facebook. I like to contribute good content to the Interwebs. On Facebook, I was mostly contributing links to articles about Facebook privacy issues. While I was taking a break from Facebook, another HN participant linked to a Wikipedia article in an HN thread, and I saw an edit I could do there that would change the close-enough-for-government work word into the exactly correct word. So I made the edit. Later I made a more substantive edit and added a recent reference to a more visited and more controversial article--on a subject much discussed here on HN. Over time, I will check how well my edits are accepted. Someday I'll try posting a whole new article, when I have a sense of what is missing and have reference materials at hand. I'll evaluate my experience by how other Wikipedians respond to my edits.
No, with an account. I happen to know a bit about a few, completely unrelated areas (the area I live in, foods from a certain country, digital music composition, a couple martial arts, computer sciency stuff, etc.) that I wanted to make substantial contributions to fill those portions of wikipedia out. About 2 and a half years ago, I signed up and made an account and started dutifully filling out information, adding new articles, editing some old ones. Normal stuff.
I probably did a few hundred edits and contributed 30 or so new articles. As far as I know, not one of those things survived the first month.
I haven't even bothered after that experience. Citing the submission guidelines led to nothing.
The cabal of super-user types there that seem to want to fix wikipedia on the current status quo (unless they themselves edit something) made wikipedia at the time unbearable as a new contributer. It wasn't like there were even requests for changes or new edits (things that wouldn't have been a problem since I was new and learning the ropes) -- just deletions. Sometimes within minutes.
It wasn't even that somebody had come along and cleaned up my submissions, or provided some editing work, just....gone.
After that wonderful experience I decided to spend those few hundred hours someplace else.
While Wikipedia (especially the English version) has its problems. That statement is an exaggeration.
You're very likely to run into these issues if you contribute to certain topics. Examples include living persons, video game characters, some piece of software you wrote, or anything else that's not very notable, controversial or hard to find references for.
However for the vast majority of topics this isn't an issue. If you're just writing about a place, landmark, some historical character, a scientific discipline or any of the topics that make up ~80% of the actual content on Wikipedia you're not going to have your article listed for deletion.