A partial list of what's new in Live 11 includes:
Comping:
Comping – Live organizes multiple passes of an audio or MIDI performance into individual takes. The best parts of these takes can be stitched together for the final result.
Linked-track editing – Link two or more tracks to edit their content simultaneously.

MIDI Polyphonic Expression:
MPE support – Add bends, slides and pressure for each individual note in a chord, add subtle expression variations, morph between chords and create evolving sonic textures more easily.
Expression View – Edit the pitch, slide and pressure envelopes of each note to refine the expression in your music.
MPE-capable native devices – Wavetable, Sampler and Arpeggiator are updated to support MPE.

New devices:
Hybrid Reverb – Combines convolution and algorithmic reverbs, making it possible to create any space, from accurate real-life environments to those that defy physical reality.
Spectral Resonator – Breaks the spectrum of an incoming audio signal into partials, then stretches, shifts and blurs the result by a frequency or a note in subtle or radical ways.
Spectral Time – Transforms sound into partials and feeds them into a frequency-based delay, resulting in metallic echoes, frequency-shifted and reverb-like effects.
Inspired by Nature – Six playful instruments and effects that use nature and physics as their inspiration. Made in collaboration with Dil

Live 11.0 Release Notes
https://www.ableton.com/en/release-notes/live-11/

Rev2: New Ableton KeyGen

Tested, working on maOS Catalina & Big Sur

home page: https://www.ableton.com/en/live/

Ableton.Live.Suite.11.v11.0.0.Rev2.macOS-GbR