The first popular markup language to emerge in the mid-80s was the Standard Generalized Markup Language (SGML), which descended from IBM's General Markup Language (GML). SGML is a broad and powerful document markup language that can be used to create other markup languages that are tailored to more specific tasks, and it is from this that HTML was developed.
In the early years of HTML, there was no governing body or organization established to set standards for the language, which left software developers free to modify HTML to suit their particular needs/products through the use of extensions. The problem, however, was that extensions intended for one particular browser would not be compatible with other browsers, which forced developers to create workarounds for their web pages, adding another layer of complexity to what was supposed to be a fairly simple markup language in the first place.
World Wide Web Consortium
(W3) was established in the later part of 1994, founded at the Massachusetts Institute of Technology Laboratory for Computer Science with the support from the
Defense Advanced Research Projects Agency
(DARPA). The goal of the W3C was to set current specifications and to ensure the agreement among industry members in the adoption of new standards in the future, providing a model for cross-platform compatibility for the content delivered over the Internet. While the W3C has no enforcement power over the standards it sets, it is generally in the best interests of everyone to have a uniform standard with regards to a particular language, though sometimes the standard is not followed in its entirety, and sometimes not within a timely manner.