Install

python -m venv .venv
.venv/bin/pip install -e ".[desktop,atlas-build,dev]"
.venv/bin/python -m tools.build_atlas    # downloads the open atlases and builds atlases/cns (about 40 s)
.venv/bin/python -m tools.build_atlas --local    # also adds sources not yet allowed to be shared
.venv/bin/mnemosyn                       # desktop app

On hybrid-GPU laptops, prime-run .venv/bin/mnemosyn uses the discrete GPU.