FLATHUB - Apps for Linux, right here
Homebrew - The missing package manager for macOS
Snap Store - An in-app shopping experience from Snapchat 🐶🔥
MacPorts - The MacPorts Project is an open-source community initiative to design an easy-to-use system for compiling, installing, and upgrading either command-line, X11 or Aqua based open-source software on the Mac OS X operating system.
AppImageKit - Linux apps that run anywhere
NixOS - 25 Jun 2014 . All software components in NixOS are installed using the Nix package manager. Packages in Nix are defined using the nix language to create nix expressions.