X3DOM (pronounced X-Freedom) is an experimental open source framework and runtime to support the ongoing discussion in the Web3D and W3C communities how an integration of HTML5 and declarative 3D content could look like. It tries to fulfill the current HTML5 specification for declarative 3D content and allows including X3D elements as part of any HTML5 DOM tree.
I had to get past two empty PR releases and finally search the Web for a useful URL.
Even the about page has a great demo. It also has links to more information.
Not stable, yet, but merits your attention for authoring topic map interfaces.
Pointers to your interfaces, topic map or otherwise, using X3DOM, greatly appreciated!