XMLFilter is one of those great examples of a unglamorous but extremely valuable program. Based on its description (and I expect to try it out and report on it in this column soon), it is a must-have for anyone building SAX programs. It provides a fallback SAX parser/driver to avoid SAXReaderNotAvailable errors that users encounter on some platforms. It also offers a safety net against the XMLGenerator bug that bit me earlier in this series. Its main feature, however, is a framework for SAX filters. See Andrew Shearer’s announcement.