The X3D ISO standard defines a runtime system and delivery mechanism for real time 3D content and applications running on a network. It supports several file format encodings and programming languages, providing unsurpassed interoperability for 3D data and significant flexibility in manipulating, communicating and displaying scenes interactively. X3D incorporates the latest advances in graphics hardware, compression and data security to provide the best performance and visual impact in an extensible architecture that supports ongoing evolution. X3D's XML-encoded scene graph enables 3D to be incorporated into web services architectures and distributed environments, facilitating the movement of 3D data between applications.
ManyOne is Digital Universe. Features a modified mozilla with a flux plugin for 3D contents.
Contigra, Based on a PdH thesis. Standardized repertoire of 3D-widgets, metaphors and interaction techniques to build intuitive and attractive 3D user interfaces. Can generate X3D (not for beginners !)
Carina is an xVRML browser (Beta in April 2005). xVRML is based on VRML97 (see same site for specifications, rationale, XSD etc.)
VizX3D is one of the first (good) X3D Authoring Tools (2004), $300. One of the Company Members is Toni Parisi (one of the two fathers of VRML). VizX3D bundles with Flux 1.2 Player.
SwirlX3D, 100$ (but only $50 for educators and students), 1 month trial (2004 - not tested) - this is the successor for Spazz3D which I found nice.
X3D-Edit X3D-Edit is a graphics file editor for Extensible 3D (X3D) that enables simple error-free editing, authoring and validation of X3D or VRML scene-graph files. Context-sensitive tooltips provide concise summaries of each VRML node and attribute. These tooltips simplify authoring and improve understanding for novice and expert users alike. Note: The windows installer writes on C:\ whatever you decide. Also you must edit the c:\ibm\xeena\Xenna.bat file and fix Java Home. The X3D Editor is in c:\www.web3edit.ord\x3d\contents. (April 2005)
You also can use any xml editor that supports DTD or XSD, e.g. Xemacs
Generators and Exporters
VRML97 to X3D Translation ( Vrml97ToX3dNist) Q. Wang's. Java-based (with sh and bat files). Java-based. TESTED @ Tecfa (works). Edit Sh and Bat files to define an absolute CLASSPATH
web3d.org, the web|3D Consortium (who make the standards)
Neocosm Neocosm.net is a non-profit community and industry portal dedicated to promoting the creation of quality real-time 3D (virtual reality) content (has a x3d section)