Now you've learned about how to create TEI documents, but we haven't said anything about what you can do with them…

There is a very wide range of things you can do with TEI documents, involving in-depth analysis, data mining, processing to discover patterns of various sorts.

We're going to focus on "publishing", both in the narrow sense of "making them readable online" and also in the broader sense of "exploiting the encoding publicly". But most of the more advanced things you can do with TEI documents use technologies similar to the ones we're talking about here.

The Extensible Stylesheet Language allows you to transform XML documents into other XML formats

Essentially XSLT allows you to map a given XML element onto another XML element: saying "take in the following construct, and put out this other construct"

It could be a construct in the same language, or in a different language such as XHTML, as in the example here

These kinds of tools are designed to manage large groups of XML files, and to provide certain kinds of advanced functionality: fast, efficient searching transformations involving groups of files: not just transforming each file separately, but doing transformations that involve taking parts of different files and creating new results files: for instance, a sorted list of the first lines from all the poems in a collection.

How do databases fit into a larger XML publication framework? What do they do? they create and store indexed information: that is, information from the source XML files that has been preprocessed to make it more accessible and easier to manipulate. For instance, they might store tables of all the document metadata (author, title, genre, date, etc.) so that it can be searched and sorted more quickly they contain a representation of the document's structure in a format that makes it easier to process, so that certain kinds of navigation are easier Within the XML publication framework, the database sits and waits for queries to come in. when it receives a query, it performs the necessary searching and returns a result (in the form of an XML fragment, or a node set, or some proprietary structure) the result can then be transformed (e.g. into HTML for delivery to a browser, or into some other XML format for other processing) using XSLT

XML databases exist as separate modules that can be used as the basis for XML publishing systems, for instance: eXist DBXML Xindice (Apache)

The tools you need, and the people you need, can be imagined as a rough continuum of increasing scale, complexity, difficulty, and cost: at the simplest level, there are things you can do (or learn to do) by yourself, with very little in the way of equipment or software: tools like XSLT and CSS will go a long way towards producing simple, effective interfaces for browsing and reading small sets of documents at a slightly more complex level, as the number of documents increases and as you want to do more ambitious things with them (such as visualizations, complex searching), you need software tools that are a little more challenging to manage: perfectly within the capabilities of a humanist, but requiring more time: not something you can do on the side of another job; this becomes someone's major job responsibility Going a bit further, we get to things that require XML publication frameworks that require a professional systems administrator, someone who really understands the installation and configuration of things like web servers, XML databases, etc. These are the kinds of tools we need to build things like data mining or text/topic analysis into our publications, and also if we want to publish larger collections of documents that require more server power/speed For production-level publication, where you may be actually charging money for access (and hence need to do things like authentication) and hence may have higher standards of performance and reliability, you need to start engaging with your institutional IT organization to make sure that things like backups, server maintenance, etc. are being handled at the appropriate level of professionalism; this is also the level of scale at which we start to be able to really work effectively with multiple large data sets: for instance, multiple projects of substantial size Finally, if we want to be able to ensure the long-term sustainability of projects, we need to engage with systems like institutional repositories and the data curators who can help us ensure that data will be maintained, migrated, etc. after the project itself is no longer funded.