The information at http://db.apache.org/derby/manuals/dita.html ("Apache Derby: DITA-sourced documentation") needs updating. Specifically –
"Apache Ant Version 1.6.2" should be changed to "Apache Ant Version 1.6.2 or later".
"Any JDK 1.4.2" should be changed to "Any JDK 1.4.2 or later".
Similarly, step 1 in "To set up your environment..." should say "Install the JDK 1.4.2 or later implementation."
A sixth step should be added to "To set up your environment...". It should say the following:
On a UNIX system, make sure that your LANG environment variable is set to "en_US.UTF-8" rather than to "C" or "en_US.ISO8859-1". (On Windows, UTF-8 seems to be the default.)
The table of manual IDs is out of date: the last line (workingwithderby) should be removed.
Under "Modifying the output format", the following sentence should be removed – it appears these changes have been incorporated into the current file.
"Jeff Levitt submitted an xsl file for improving the PDF output here [link]."
I would fix these myself, but I don't have the tools to fix the website.