Lutris is an open source gaming platform for GNU/Linux. It makes gaming
on Linux easier by taking care of managing, installing and providing
optimal settings for games.
Lutris does not sell games, you have to provide your own copy of the games
unless they are Open Source or Freeware.
The games can be installed anywhere you want on your system, the tool
does not impose anything.
Lutris relies on various programs referenced as 'runners' to provide a
vast library of games. These runners (with the exception of Steam,Desura
and Web browsers) are provided by lutris, you don't need to install them
with your package manager.