HyTime stands for Hypermedia/Time-based Structuring Language. It is a markup language used for encoding hyperlinks and other multimedia structures in XML documents. Since 1992 HyTime is an ISO 10744 Standard providing a hyperlink and addressing mechanism.

Currently HyTime is not widely used, but it is very important for the processing of SGML and XML-based Hypermedia technology. The specification provides many mechanisms to create various link types, which can be used to describe relations to, from, within and between any kind of objects. It is possible to create not only both unidirectional and bi-directional links, but also links among more than two resources.

At the first sight, it seems that HyTime is similar to XLink. The similarity in abstract linking models between the two techniques allows the translation from HyTime-based links to XLink-based links. Although both techniques have essentially the same linking structures and semantics, there are significant differences between HyTime and XLink. Firstly, there are a few syntax differences. Secondly, unlike XLink, HyTime can provide any form of indirect addressing. XLink is most appropriate for Web-based delivery and therefore not ideal for indirect addressing.