There are many alternatives to Synaptic for Linux if you are looking for a replacement. The best Linux alternative is Homebrew, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to Synaptic and many of them are available for Linux so hopefully you can find a suitable replacement. Other interesting Linux alternatives to Synaptic are Advanced Package Tool (Free, Open Source), pacman (package manager) (Free, Open Source), aptitude (Free, Open Source) and GNOME Software (Free, Open Source).
Software lets you install and update applications and system extensions. A plugin system is used to access software from different sources. Plugins are provided for: Traditional package installation via PackageKit (e.g. Debian package, RPM).