+in tarball. Following ones are tested to work with:
+@url{http://www.goredo.cypherpunks.ru/, goredo} (NNCP's author creation),
+@url{https://redo.readthedocs.io/, apenwarr/redo} (@code{contrib/do} is
+from that project), @url{https://github.com/leahneukirchen/redo-c, redo-c},
+@url{https://github.com/gotroyb127/baredo, baredo}.