Oxygen XML Editor

Oxygen is a full-featured XML editing and development environment. It is suitable for both text encoders and XML developers. For developers, it includes an Eclipse plug-in. IU has a site license for this product, a Java application available for Mac OS, Unix/Linux, and Windows. After installing the application you will be asked to paste the license text into a dialog box. See below for downloads links and the license.

Oxygen Dowloads
Oxygen Site License Key

TEI2HTML Stylesheets

These stylesheets, developed for The Swinburne Archive, convert TEI documents to XHTML. There are a number of parameters that may be set to modify the output. There is some documentation in the bundle and embedded in the tei2html-conf.xsl file.
tei2html.tar.gz

TEI Utilities

• sgml2tei.pl. This perl scripts converts a flavor of SGML to something closer to TEI/XML. Converted
  document should be well-formed XML, but not quite valid TEI. Document will require additional editing to make valid.