What is your favorite FOSS for music making / performance?

Feel free to describe what you use it for, and how you use it.

PD? Supercollider? Ardour? Zrhythm? LMMS? Bespoke? Csound?

Something completely else?

Give me all your thoughts 💙

(FOSS only, because.. you know.. political reasons... And I already know enough about the corporate mainstream softwares)