+# Check for docbook programs
+AC_ARG_VAR(DOCBOOK2MAN, [docbook2man path])
+AC_PATH_PROG(DOCBOOK2MAN, [docbook2man], [])
+if test -z "$DOCBOOK2MAN"
+then
+ AC_MSG_WARN([docbook2man not found, man pages rebuild will not be possible])
+fi
+
+AC_ARG_VAR(DOCBOOK2HTML, [docbook2html path])
+AC_PATH_PROG(DOCBOOK2HTML, [docbook2html], [])
+if test -z "$DOCBOOK2HTML"
+then
+ AC_MSG_WARN([docbook2html not found, man pages rebuild will not be possible])
+fi
+
+# Check for python-sphinx
+AC_ARG_VAR(SPHINX, [sphinx-build path])
+AC_PATH_PROG(SPHINX, [sphinx-build], [])
+if test -z "$SPHINX"
+then
+ AC_MSG_WARN([sphinx-build not found, documentation rebuild will not be possible])
+fi
+
+# Check for graphviz (dot)
+AC_ARG_VAR(DOT, [dot path])
+AC_PATH_PROG(DOT, [dot], [])
+if test -z "$DOT"
+then
+ AC_MSG_WARN([dot (from the graphviz suite) not found, documentation rebuild not possible])
+fi
+