The last few years have seen the emergence of various content-oriented XML-based, content-oriented markup languages for mathematics on the web, e.g. OpenMath, Content MathML, or OMDoc. These representation languages for mathematics make the structure of the mathematical knowledge in a document explicit enough so that machines can operate on it. Other examples of content-oriented formats for mathematics include the various logic-based languages found in automated reasoning tools, program specification languages. The promise if these content-oriented approaches is that various tasks involved in doing mathematics (e.g. search, navigation, cross-referencing, quality control, user-adaptive presentation, proving, simulation) can be machine-supported, and thus the working mathematician is relieved to do what humans can still do infinitely better than machines: The creative part of mathematics --- inventing interesting mathematical objects, conjecturing about their properties and coming up with creative ideas for proving these conjectures. However, before these promises can be delivered upon (there is even a conference series studying Mathematical Knowledge Management (MKM)), large bodies of mathematical knowledge have to be converted into content form.

In the sTeX project it is investigated how the macro language of TeX can be used to transform into an MKM format by supplying specialized macro packages, which will enable the author to add semantic information to the document in a way that does not change the visual appearance. This process is also referred to as semantic pre-loading and the collection of macro packages is called Semantic TeX (sTeX). Thus, sTeX can serve as a conceptual interface between the document author and MKM systems: Technically, the semantically pre-loaded LaTeX documents are transformed into the (usually XML-based) MKM representation formats, but conceptually, the ability to semantically annotate the source document is sufficient.