Do you know which non-free software are installed on your Linux box? Though many distros ship only free software, the non-free ones may get installed over the course of time. The vrms (Virtual Richard M. Stallman) package identifies these packages. It checks the licenses of all software installed on your box and lists the ones which are non-free. It is particularly useful for Debian-bases systems.
Before going further, we should understand the differences between two important terms from the Debian point of view:
non-free: as the name suggests, these are not free. However, they are redistributable.
non-freesoftware is not considered as part of Debian.
contrib: these packages are free themselves but depend on
non-freepackages. Not considered as part of Debian.
To install vrms on Ubuntu, run:
$ sudo apt install vrms
To list all
contrib packages, run:
$ vrms -e Non-free packages installed on tux intel-microcode Processor microcode firmware for Intel CPUs rar Archiver for .rar files unrar Unarchiver for .rar files (non-free version) Contrib packages installed on tux iucode-tool Intel processor microcode tool libdvd-pkg DVD-Video playing library - installer thunar-dropbox-plugin context-menu items from dropbox for Thunar virtualbox-5.1 Oracle VM VirtualBox 3 non-free packages, 0.2% of 1744 installed packages. 4 contrib packages, 0.2% of 1744 installed packages.