VRML stands for Virtual Reality Markup Language.  It parallels HTML (Hyper Text Markup Language) in many ways in that links to other web pages or VRML Worlds can be created.  Essential the difference between HTML and VRML is that instead of the media being presented in "Hyper Text" it is presented in Virtual Reality.  This essentially means that instead of a world that you can only simply explore in two dimensions (with scroll bars), you have world that can be explored in three dimensions (basically moving some object up or down, left and write, or marking it bigger and smaller).  VRML is simply a 3 dimensional space to explore with links to other space 2 or 3 dimensional spaces.

There are two standards of VRML, VRML 1.0 and VRML 97.  The VRML 97 standards replaced the VRML 2.0 standards in an international convention in February of 1997.
 
 

In order to understand why molecules have certain properties and what happens in certain chemical reactions, it is essential to know the geometry of a molecule(This is essential in complex biochemical processes such as enzyme-substrate binding).  Any many cases a two dimensional presentation is not nearly adequate for understanding these reactions between molecules or properties of molecules.  Thus, we have molecular modeling, which just the same as using tinker toys to build models only that now we can do it on a computer and perform complex calculations.  Molecular Modeling files have different file formats, the most popular one being pdf (protein database file, can be used for any molecule not just proteins).  The most important aspect of science is not simply discovery but communication.  The best means to communicate these molecular models is via the internet.  The first means of doing this was through simply going to a web site, downloading a molecule (in pdf format,etc.) and opening a molecular model viewer.  However,  these molecular viewers can be a bit pricy, from $50-$3000, and also take up valuable hard drive space.  Also, what if someone just wants to see what water looks like, they shouldn't have to download the file and then go buy a program that costs at least $50 and takes up a minimum of 20MB.  Thus, free molecular viewers as plug-ins were developed, but once again one runs into issues of having an entire program just to view molecules.  VRML is perfect because it is a universal language that is not only used for molecules but every other virtual world imaginable.  So, we not only have a molecule viewer that is universal such as HTML, but we can create links from different parts of a molecule to information about that part of a molecule.  Also, with VRML 2.0 we can animate these molecules to show vibrations, chemical reactions, etc.....