+# external manpages which we host ourselves, since some packages
+# (currently just Xapian) doesn't host manpages themselves.
+xtxt :=
+xtxt += .copydatabase.1
+xtxt += .xapian-compact.1
+xtxt := $(addprefix Documentation/.x/, $(addsuffix .txt, $(xtxt)))
+xdocs := $(xtxt)
+xdocs_html := $(addsuffix .html, $(subst .txt,,$(xtxt)))
+gz_xdocs := $(addsuffix .gz, $(xdocs) $(xdocs_html))
+rsync_xdocs := $(gz_xdocs) $(xdocs_html) $(xdocs)
+xdoc: $(xdocs) $(xdocs_html)
+
+Documentation/.x:
+ mkdir -p $@
+
+Documentation/.x/%.txt :: | Documentation/.x
+ $(PERL) -w Documentation/extman.perl $@ >$@+
+ mv $@+ $@
+
+Documentation/.x/%.html: Documentation/.x/%.txt
+ $(txt2pre)
+