gem 1:0.94-8build1 (amd64 binary) in ubuntu mantic

 Gem is a loadable library for Pure Data (Pd), which adds OpenGL graphics
 rendering and animation to Pd. Pd is a graphical programming language and
 computer music system.
 .
 This package contains the core library.
 If you want to use external data (live video capture, film footage, still
 images, ...), you have to install one (or all) of the gem-plugin-* packages.