Regulation of receptor concentration by homologous hormone. Effect of human growth hormone on its receptor in IM-9 lymphocytes.

Hypertext, which we generalize as hypermedia, is text plus links: an extra degree of freedom to move around, other than starting at the beginning and reading all the way to the end. By this definition, the ubiquitous World-Wide Web is a mediocre specimen. True, the Web is a cosmopolitan system of unprecedented scale, with instantaneous global reach, that is characteristically easy to deploy and extend. Hypermedia, however, is nothing without links, and the Web’s links are brittle (they routinely break), one-way (you can see links out but not links in) and untyped (anemic support for telling what a link means). This results in big clumsy documents with few if any links (that often go nowhere), no backlinks, ambiguous, ad-hoc data semantics, and poor reuse of content. The sparsity of the Web, as it comes off the shelf, means: have to read a lot per unit of information gleaned need to maintain separate documents for distinct audiences have to continually reinvent the same basic functionality duplicates and goes stale, causing people to be misled these points aside, this bias spells a missed opportunity for building out an entire universe of creative expression. only are there copious practical reasons for addressing these issues, doing so would dramatically boost the Web’s capacity for communicating complex ideas, making subtle arguments, and fostering innovative methods of storytelling. Turning the Web into truly dense hypermedia entails being able to reliably point to a very large number of very small objects, and doing that in turn means designing a system—a protocol—for maintaining the stability and continuity of the addresses (URLs) exposed.