ArXiv

arXiv is a preprint archive, serving up unreviewed papers in "Physics, Mathematics, Computer Science, Quantitative Biology, Quantitative Finance and Statistics." It is the standard way to quickly get the word out (and stake out credit) in physics, particularly particle physics and astrophysics.

Anyone can upload a paper to arXiv if they have an endorsement, leading to the expected seas of green ink. Fortunately, papers for most topic categories require at least one other person to endorse them and the moderators are quite experienced in dealing with cranks. The unfiltered topic categories ("general physics", "general mathematics") are pretty much "abandon brain all ye who enter here." Whether that paper appears in the intended category is determined by the moderators, who in many cases are anonymous.

viXra
In defence of the spirit of free science and enquiry, viXra (an arXiv of their own) was founded "by scientists who find they are unable to submit their articles to arXiv.org because of Cornell University's policy of endorsements and moderation designed to filter out e-prints that they consider inappropriate."

Given some of the lunacy available on arXiv, you can guess what sort of content viXra accumulates: lots of Electric Universe crankery and occasional global warming denialism, and "proofs" of famous mathematical conjectures, notably the and the, which for some reason no serious mathematician gives a hoot about. viXra also directly invokes the Galileo gambit with their blog category "'Crackpots' who were right".

viXra also features blog-style comments for each abstract, which are a delight even by the standards of the bottom half of the Internet.

The scientific world is mostly amused, insofar as it takes any notice at all. The founder claims some papers of value that made it to peer-reviewed publication, though.

The culmination of the entire viXra knowledge is being condensed in a single, high-density website, called Vixrapedia.

snarXiv
The other alternative to arXiv's oppressive and hidebound strictures, the snarXiv generates abstracts of papers that damn well should exist. Play arXiv vs snarXiv and see how well you can avoid Sokaling yourself!

Ruining the joke
arXiv is pronounced as archive; In Greek, the capital letter chi (Χ) became ex (X) in the Latin alphabet by way of Etruscan.