Once, a web application server, though it appears that Sun bought and burried it. http://www.netdynamics.com
Oh, yes they did. ScottMcNealy playing poker with investor's money like he always does. The story went that Sun needed an app server, and ND was the second in the marketplace, so they bought it. But after that they also bought Netscape App Server (former Kiva), and they had to throw away one. Since NetDynamics was the most incompatible with the anti-patterns collected under the label of J2EE, it got sacrificed. Now after 4 years they came with a written from scratch app server, because Netscape apperver was renowned for its technical failures and customer just couldn't trust it. They are now claiming and spreading the news on all the dev forums that the new Sun App Server is a total rewrite. What can you say, on one hand you're happy that you get java for free, but on the other hand enjoying this at the expense of all those anonymous investors whose money were lost by Sun is almost indecent.
Some wikizens have praised this bit of software. What was so great about it?
Well, first of all, it worked. Back in 1997 when servlets were not on the radar screen this one was handling on-line banking. It had load balancing and all the features, minus EJB of course. It also ran on hardware platforms on which you can't even begin to install WebSphere or WebLogic.
Second, it got pretty much everything right, some of its concepts are slowly catching up in the latest Sevlet specification. Little thingies like Server Global Session, and application and page lifecycle that was only available in Servlet 2.3, and they never made the mistake to hodge-podge HTML syntax with Java syntax in the well known style of ASP and JSP.
I think it's worth mentioning that it had a component oriented architecture that is now reinvented under the JavaServerFaces spec, and we still have to see them in action. It was also kind of emulated by the .NET framework, but both Java and .NET alternatives have a programming API like an order of magnitude more complex. I think I praised ASP.NET for its similarity with NetDynamics, but recently, upon studying the framework more closely I found it suffering from unnecessary verbosity, which is something the designers of ND carefully avoided.