Whether using jing to validate the RELAX NG schema against itself, or Saxon to transform the XSLT stylesheet with itself, the java virtual machine required more RAM than the defaults set on my machine. At 4 MiB of stack space (-Xss4m) jing ran out; at 8 MiB it did not. Saxon did not need extra stack space, but craved an extraordinary quantity of heap space. Astoundingly (at least to me), at 5 GiB of heap space (-Xmx5g) it bombed; with 6 GiB it ran.