They are both game creation platforms allowing you to create little retro games and download others games, Which I will add, Is on topic. A simple Google Search result yields the following results:
Pico-8 (Their website is https://www.lexaloffle.com/pico-8.php, and more about this on the forum here.):
PICO - 8 is a fantasy console for making, sharing and playing tiny games and other computer programs.
LOVE (Their website is https://love2d.org/ and see this guide on the forum for installation.):
LÖVE is an awesome framework you can use to make 2D games in Lua. It’s free, open-source, and works on Windows, Mac OS X, Linux, Android and iOS.