Web3D Tool #2 - Vivaty (formerly Flux) Studio
Although Vivaty Studio is a 3D modeling and animation application, the real value add of this application is the web3D authoring. I highly recommend Vivaty Studio for 3D artists and programmers.
For artists and those slightly familiar with standard 3D modeling software, it has a user-friendly UI to get one creating interactive content in no time. Simple wizards and drag/drop menu features can add basic functionality to 3D objects in a few clicks. Animations can be made in Vivaty Studio with a simple animation time-line or imported directly from other DCC tools (personally found COLLADA imports work best). Most of the 3D artists I work with love working with Vivaty Studio as it allows them to create interactive 3D without having to know anything about programming.
For programmers, a great tool to quickly assemble scenes in, more fun to look at than code all the time, and an "Advanced" menu where you can add Scripts, Routes, and more for deeper levels of interaction and functionality. I love the "Export text to clipboard" feature as it is great when I want to hack the code in a standard text editor (Notepad, Wordpad) or X3D Edit.
Keith Victor (co-founder Vivaty) has done a great job on this tool over the years. It has changed a few names, but still only gets better in its features and usability. Another great tool for those wanting to build the 3D web. Make sure to check out the Vivaty Create Contest announced with Vivaty Studio's release.