What is LiveJournal?
LiveJournal is an online journaling community built around personal journals started in March, 1999 by Brad Fitzpatrick. Mostly written in Perl and using MySQL for it's database back-end, it's an open source project that has drawn over 1,000,000 users in addition to hundreds of volunteer developers and technical supporters who are dedicated to supporting the project. Overseen by a small paid staff, it is funded entirely by its members and kept running by its volunteers. It has spawned a few other successful online communities, most notably DeadJournal and uJournal.

In the summer of 2001, LiveJournal.com put an invitation code system in place to regulate growth because the site had slowed to a halt and the creation of journals solely to harass users had become a common problem. In order to create an account you had to obtain an invitation code from a current user or purchase an account. Although LiveJournal was still growing very quickly, invitation codes slowed the growth and have eliminated a lot of abuse.

Invitation codes were removed on December 12, 2003 and you can now create a free account without anything more than a valid E-mail address and after either a visual or audio test to try to prevent mass account creation.

Who's Frank the Goat?
When Brad was living in the dorms at UW, his roommate decided to make a few joke banners to put up on Brad's site FreeVote.com. Brad and his roommate ran out of ideas after banner #4 and started making banners saying "LiveJournal.com... because goats are cool." So, Brad went and found a picture of a goat and he became the unofficial LiveJournal mascot. You can find the original banners here: http://www.livejournal.com/banners.bml and read Frank's story here: http://www.livejournal.com/site/goat.bml

Why LiveJournal instead of all these other web log tools?
LiveJournal caters to Internet users of all levels. It simplifies the process for the computer newbie and makes it possible for anyone to create the journal of their dreams, complete with flashing graphics and flashing links. At the same time even the experienced programmer can find something new to play with and contribute to the project. People can comment on each other's entries, log in securely, download their journals, tag entries from any journal or community as memories, form communities, filter their entries so only select people can see them, and update from a number clients that have been developed for a number of platforms and include the very popular logjam client developed by Evan Martin. In short, the difference is that LiveJournal is a community and not just a site that hosts personal web logs.

LiveJournal.com has received a number of awards, including two People's Voice Awards, one each for "Service" and "Personal Web Site", during the 5th Annual Webby Awards.

It's also worth noting that LiveJournal supports RSS feeds and entries from both other sites using the LiveJournal code and feeds from sites such as Slashdot and Dilbert can be read via LiveJournal, making it a more useful place to center your Internet life around. Recent features inclue audio posting via the phone, a rich text web client, posting via E-mail with PGP encryption, a number of different styles to apply to your journal and an inproved creation and customization system, increased file capacity and the ability to purchase more user picture icons if desired.


Sources:
http://www.livejournal.com/doc/server/
http://www.livejournal.com/support/faq.bml
Information also gathered from my experiences volunteering for LiveJournal.com and conversations with other volunteers and staff members.