From the Preface of the TEI Guidelines for Electronic Text Encoding and Interchange:
These Guidelines are the result of over five years' effort by members of the research and academic community within the framework of an international cooperative project called the Text Encoding Initiative (TEI), established in 1987 under the joint sponsorship of the Association for Computers and the Humanities, the Association for Computational Linguistics, and the Association for Literary and Linguistic Computing.The impetus for the project came from the humanities computing community, which sought a common encoding scheme for complex textual structures in order to reduce the diversity of existing encoding practices, simplify processing by machine, and encourage the sharing of electronic texts. It soon became apparent that a sufficiently flexible scheme could provide solutions for text encoding problems generally. The scope of the TEI was therefore broadened to meet the varied encoding requirements of any discipline or application. Thus, the TEI became the only systematized attempt to develop a fully general text encoding model and set of encoding conventions based upon it, suitable for processing and analysis of any type of text, in any language, and intended to serve the increasing range of existing (and potential) applications and use.
What is published here is a major milestone in this effort. It provides a single, coherent framework for all kinds of text encoding which is hardware-, software- and application-independent. Within this framework, it specifies encoding conventions for a number of key text types and features. The ongoing work of the TEI is to extend the scheme presented here to cover additional text types and features, as well as to continue to refine its encoding recommendations on the basis of extensive experience with their actual application and use.
We therefore offer these Guidelines to the user community for use in the same spirit of active collaboration and cooperation with which they have so far been developed. The TEI is committed to actively supporting the wide-spread and large-scale use of the Guidelines which, with the publication of this volume, is now for the first time possible. In addition, we anticipate that users of the TEI Guidelines will in some instances adapt and extend them as necessary to suit particular needs; we invite such users to engage in the further development of the Guidelines by working with us as they do so.
Like any standard which is actually used, these Guidelines do not represent a static finished work, but rather one which will evolve over time with the active involvement of its community of users. We invite and encourage the participation of the the user community in this process, in order to ensure that the TEI Guidelines become and remain useful in all sorts of work with machine-readable texts.
Recently (March '99), a TEI consortium has been founded. From the WWW page:
A new consortium has been formed for the maintenance and continuing work of the Text Encoding Initiative (TEI). The TEI is an international project to develop guidelines for the encoding of textual material in electronic form for research purposes; until now, it had been organized as a simple cooperative effort of the three sponsors, and funded solely by grant funds. Now four universities have agreed to serve as hosts for the new consortium, and the three organizations which founded the TEI and have governed it until now have agreed to transfer the responsibility for maintaining and revising the TEI Guidelines to the new consortium.