A typical invocation would be on a Unix command line:
# make the special TeX format file (first time only) pdftex -ini "&pdflatex" fotex.tex # run an XSL processor xt file.xml somestyle.xsl file.fo # run pdfTeX on the result; twice, to make sure # referencing and pagination is stable. pdflatex "&fotex" file.fo pdflatex "&fotex" file.fo # look at the result acroread file.pdf
Most modern TeX implementations contain pdfTeX.