Slashdot is a forum originally intended for computer nerds — thus the slogan. It has been around since the 1990s. The people who run the forum post links to articles and summaries of these articles; the members then post comments on these articles. The articles are open for comment for about two-weeks to a month, but most of the comments that will be noticed will be posted in the first 48 hours.
So, what makes this different from all the other fora that do this? Technical fora are a dime a dozen, after all...
Slashdot has a special moderation system and a meta-moderation system. Any member with sufficiently good karma (that is, a record of making good comments) can be randomly picked to moderate posts in any discussion they are not commenting in. They only get a limited number of mod points to do it with, though. Members also get the chance to vote on whether someone else's moderation is good or not, which (at least in theory) makes sure the mod points go to people who know a good comment from a hole in the ground. This method plus the default threshold hide the worst (or most obvious) trolling and vandalism from the average reader.
This is a good thing, because posts quite literally can never be changed or deleted once they are posted. All posts are locked immediately, and all threads are locked eventually.
Anyone can read the articles. Anyone can post, but if they aren't a member they have to post as "Anonymous Coward." There is a limit to how often you can post which is related to your karma on the site. Membership is free but permanent; once you have an account, you can't remove it (though you can stupidly forget the password). Every account has a unique username and a number. You can subscribe, which has benefits — earlier access to stories, the ability to see your entire archive, etc.
Traditional topics on Slashdot involve Linux, BSD, other open-source things (there are many fans of the Free Software Foundation), development, Apple Inc., and videogames. Windows comes up quite a bit, but no one will admit to liking it. Most members of Slashdot automatically assume that the people they are talking to are technically experienced, though there's still plenty of room for discussion and debate.
"Your Rights Online" became important early in the 21st century — after what happened to Napster 1.0, how could it not? — and has become a major enough focus that the "online" part is often all but ignored. There is also a politics session, and politics (legal and otherwise) is discussed more freely there than on some political boards. (If you look hard enough, you can find people arguing for capitalist anarchy or people who appear sincerely to disbelieve in global warming.) These things have taken on an importance there that they don't have in most other technical fora, leading to a variant of the open roleplaying problem — members sign up because of the YRO, and this annoys the older hands.
Whenever a site unprepared for large amounts of web traffic is featured on Slashdot, it may often become unreachable within minutes (if not seconds) of the article linking to it being posted because of numerous attempts by Slashdot readers to view the site in question. These sorts of unintentional DDoS "attacks" have their own name: "Slashdotting".
Warning: this board is not for the faint of heart, especially if you are there for the softer sciences.
This website provides examples of:
- Digital Piracy Is Evil: An openly Defied Trope, though there are members who do believe it.
- Emoticon: ASCII only, and rarer than some boards, but they turn up.
- In-Joke: A rich source of these. Even the name of the site is a joke: the address spoken aloud would (at the time of founding) have gone like "httpnote colon slash slash slash-dot dot org." It was intended to create confusion.
- Internet Jerk: It was extremely common to post links to shock sites, usually through redirects.
- Message Board: The centers of the site.
- Multiple Choice Form Letter: Discussions about methods of fighting Internet spam often bring replies based on this form letter.
- Scunthorpe Problem: Slashdot's lameness filter appears to impose a limit of four times that the word "troll" can be used in a post. This forces people discussing game controllers to self-censor themselves, such as use of "gamepad" in this post.
- Too Clever by Half: A significant chunk of the userbase are hardcore geeks (of varying degrees of maturity), and it shows. Also, in its earliest years, Slashdot was strongly connected to the hacker culture, and they can be somewhat condescending to people they view as corporate drones and legal jackasses.