About X (エックス)
X is an apocalyptic story set in Tokyo in 1999 (thus the series' english name X/1999), revolving around two opposing groups: the Chi No Ryu (Dragons of Earth), the Seven Angels (the actual word used is not angel, but ore like imperial messenger... harbinger, if you will), who mean to cleanse the Earth of humanity's corruption; and the Ten No Ryu< (Dragons of Heaven), the Seven Seals, who are trying to save humanity and civilization as we know it.
Despite the story's insistence on predestination and its grand scatological theme, X is the story of the individuals involved in a cosmic struggle; it is about their motivations and wishes, and ultimately about the things that lead each of them to either accept or reject the role destiny assigned to them. As such, the quote perpetually looming over the story ("their destiny was foreordained") is as much a statement as it is a question which only the characters themselves will be able to answer.
Even though X can be called a group drama (altough admitedly a very unbalanced one), the plot centers around Shirou Kamui, a young man whose destiny is to decide the Earth's fate by choosing to lead either the Seals or the Angels. Monou Fuuma, Kamui's childhood best friend and "twin star", is the story's antihero and has been becoming increasingly more important as the series progresses, to the point where now he seems to be very much the main catalyst to X's inminent climax (and yes, he is also my all-time favorite character).
At present, there are 18 published tankoubons and it's been over ten years since it started, making it CLAMP's longest running series. Sadly, X is currently on an indefinite hiatus; possible reasons being Mokona's rumoured arthrities and/or their desire to focus their energy on newer, more popular series like Tsubasa Reservoir Chronicle. Although there has been no official statement as to when it will be picked up again, both Ohkawa and the editor of Asuka (the magazine in which it's always run)have specifically said that X will be finished, eventually.
Ohkawa has also said that the story is aproaching its end. It is a generally held assumption that it will be 19 to 21 volumes by the time it's finished (I personally say 20... for why, see the tarot section).
X has been animated twice. First in 1997, in a 90 minute movie called "X: The Destiny War". The movie was superbly animated, but many fans dislike it because it was simply unable to encompass such a detailed, complicated story. It had minimal character development, at least if compared to the manga, and is a very simplified version of the plot.
Between 2001 and 2002, X was made into a 24 episode anime series. The first half of it follows the manga fairly closely, if slowly. The second half seems rather more rushed, and since X is still unfinished, it breaks away from the manga after a certain point. The anime series' biggest flaw, in my opinion, is that it leaves out the humor that often alliviates the story's grimness, and that it also leaves out certain scenes that give the characters added depth and humanity.