The bogofilter package will validate its SGML/XML documents prior to building either derived versions or the distribution tarball. The names of required packages differ greatly among the various distributions, some don't ship with the needed packages at all. Here's what packages are needed (assuming all their dependencies are installed as well according to the respective packager's directions): Mandrake Linux 9.1: HTML: OpenSP or openjade, HTML document type definitions installed manually XML: docbook-dtd412-xml, libxml2, libxml2-utils SuSE Linux 8.2: HTML: opensp, html-dtd XML: libxml2, libxslt, docbook_4, xmlto (needs to be installed manually) FreeBSD: HTML: jade or openjade, html XML: xmlto If you encounter a slew of errors, it may be necessary to create a catalog file. The following line will create the needed file for a Mandrake system (with html-4.01.tar.gz installed in /usr/share/sgml/html/): echo 'CATALOG "/usr/share/sgml/html/catalog"' > catalog vim:tw=79 com=bf\:* ts=8 sts=8 sw=8 ai: