This time last Christmas, medical blogs and RSS feeds were the hot technology topics, and we were debating the merits of newer models of scholarly publishing in web 2.0, such as open access and medical wikis.1 Can web 3.0 be here already?

Recently, a neurologist devised an apt medical metaphor for web 3.0. He suggested that, “The development of the graphical web from its early days in 1995 to the social web of late 2007 is comparable to the developing brain.” He went on to say that, “Whereas web 1.0 and 2.0 were embryonic, formative technologies, web 3.0 promises to be a more mature web where better ‘pathways’ for information retrieval will be created, and a greater capacity for cognitive processing of information will be built.” (Personal communication, A Wong, 2007.)

So what is web 3.0, and why is it called the semanticweb (table⇓)? Although both terms are used interchangeably, they convey slightly different, if complementary, views of the new web. The web 3.0 label is often used as a marketing ploy for “the next big thing.” An important feature of web 3.0 is that it enables computers to talk to each other so that they can perform the tasks necessary for us to do our work. However, a primary feature of web 3.0 is that it uses metadata—data about data. This will transform the web into a giant database, and organise it along the lines of PubMed, or one of our trusted medical library catalogues.2