> Of more recent software "clones", there is guix vs nix, mcron vs vixie-cron, shepherd vs systemd, gnutls vs openssl, all high-quality implementations of good

> Of more recent software "clones", there is guix vs nix, mcron vs vixie-cron, shepherd vs systemd, gnutls vs openssl, all high-quality implementations of good ideas. Shepherd is hardly a clone of systemd. It's older and has much fewer features. They are both init systems. The relationship of Guix and Nix is also not that of rivalry. Guix uses the Nix daemon and subscribes to the idea of functional package management, but everything else is quite different. (I realise you put "clone" in quotes and wrote "all high-quality implementations of good ideas", but I thought I should clarify anyway.)