While the information above is generally correct, there are some inaccuracies. When Image started it was a place where creators could own their own work. Unfortunately, most of them had no experience writing, only drawing, and much of the early Image output, while often beautiful, was crap as far as storytelling or compelling characters went. Pretty pictures can maybe get someone to buy a handful of issues, but after that it gets boring, which is part of the reason Image faded in a couple years (although a general downturn in the market, which was partly caused by Image’s domination but mostly a result of behind-the-scenes battles over distribution was also a major factor). The Image folks also had a lot of problems with late books, partly due to inefficiency/laziness (self-motivation is hard for some folks), partly due to the lack of editorial/administrative support which they gave up when they left Marvel, partly due to perfectionism, etc.
El Elvis Rojo says that Image split into a handful of small companies. That’s incorrect, it was essentially always organized in this way, as an affiliation of partners who did their own work separate from anyone else, and some of whom owned their own studios which published work from other creators. However, in the beginning this wasn’t really publicized to the fan community (and the absence of a mature mainstream comics news source made it so the average fan on the street didn’t know as much about the medium as we do today). The fact of this loose affiliation was further obfuscated by the fact that in the beginning the Image characters shared the same “universe” just as Marvel or DC characters did, despite the fact that they were all owned by separate folks. Once Image started splitting up, this became impracticable.
Elvis is right that the partners eventually threw Liefeld out of the group. I think the unbiased history of that has yet to be written, but it probably had something to do with his chronic lateness. Some time later, Jim Lee took Wildstorm studios (home of WildC.A.T.S., Stormwatch, and Astro City) out of Image and eventually sold it to DC.
As it exists now, Image provides a place where people can create material, get it published, and keep the rights. It’s probably the biggest publisher that specializes in primarily creator-owned work and is typically more mainstream than other creator-ownership publishers like Oni or Avatar, but exactly what a given Image book is going to be like depends on its owners, not on Image itself.
As for the original Image books, Spawn is still published although McFarlane no longer works on it regularly, CyberForce, WildStar, Shadowhawk, and plenty of other books from that era are gone. Erik Larsen is still writing and drawing Savage Dragon, which recently passed issue #100. As for the books published by Wildstorm, as a result primarily of Warren Ellis’s revamp of Stormwatch (later becoming The Authority) and some efforts by Alan Moore, the Wildstorm Universe is a grittier, more noirish super-hero universe than any other. Several sophisticated books are being published by the imprint that have essentially nothing to do with the superteam slugfests of early WildC.A.T.S. or Stormwatch. These include Micah Wrights’s Stormwatch: Team Achilles (the newest version of UN strike team Stormwatch, made up of regular humans who kill rogue SPB’s), Joe Casey’s WildC.A.T.S. 3.0 (volume 3 of WildCATS which is about a super-team gone corporate), and Ed Brubaker’s Sleeper, about life in the super-powered urban espionage biz.
–Cliffy