Cubase
Steinberg's 1989 sequencer that started on the Atari ST and ended up defining how audio software talks to plugins and sound cards.
Hamburg-based Steinberg released Cubase as a MIDI sequencer for the Atari ST, whose built-in MIDI ports had made it the studio computer of choice. Audio recording followed in the nineties, and with Cubase VST in 1996 Steinberg introduced VST — the plugin format that turned effects and synths into software anyone could write. A year later came ASIO, to get around Windows' audio latency.
Both standards outlived their rivals, which means a German software house has effectively set the interfaces for the whole industry, competitors included. Yamaha has owned Steinberg since 2004. Cubase remains a full-featured DAW, particularly strong in Europe and among film composers, while Pro Tools got the studios and Ableton got the stage.