+# Check for docbook programs
+AC_ARG_VAR(DOCBOOK2MAN, [docbook2man path])
+AC_PATH_PROG(DOCBOOK2MAN, [docbook2man], [])
+if test -z "$DOCBOOK2MAN"
+then
+ AC_MSG_ERROR([docbook2man not found])
+fi
+
+AC_ARG_VAR(DOCBOOK2PDF, [docbook2pdf path])
+AC_PATH_PROG(DOCBOOK2PDF, [docbook2pdf], [])
+if test -z "$DOCBOOK2PDF"
+then
+ AC_MSG_ERROR([docbook2pdf not found])
+fi
+
+AC_ARG_VAR(DOCBOOK2HTML, [docbook2html path])
+AC_PATH_PROG(DOCBOOK2HTML, [docbook2html], [])
+if test -z "$DOCBOOK2HTML"
+then
+ AC_MSG_ERROR([docbook2html not found])
+fi
+
+# Check for rst programs
+AC_ARG_VAR(RST2HTML, [rst2html path])
+AC_PATH_PROG(RST2HTML, [rst2html], [])
+if test -z "$RST2HTML"
+then
+ AC_MSG_ERROR([rst2html not found])
+fi
+
+# Check for graphviz (dot)
+AC_ARG_VAR(DOT, [dot path])
+AC_PATH_PROG(DOT, [dot], [])
+if test -z "$DOT"
+then
+ AC_MSG_ERROR([dot (from the graphviz suite) not found])
+fi
+