Apache Xalan is a XSLT processor that transforms XML documents into other formats (text, (X)HTML, or other XML).
Here is simple file that should be put in the root directory of Xalan (my is C:\JavaSoft\Apache\xalan-j_2_6_0), and can be invoked like this:
cd C:\JavaSoft\Apache\xalan-j_2_6_0
xalan.bat samples\SimpleTransform\birds.xml
samples\SimpleTransform\birds.xsl
samples\SimpleTransform\out.xml
There is only two lines above, I had to split the second. It is useful when trying out XSLT, so you don't have to write a new agent / class every time you have new files you want to transform.