Reaper

Music Production
Transport
SPACE Play / Stop Win mac Linux
CTRL+SPACE Record Win Linux
+SPACE Record mac
HOME Go to beginning Win mac Linux
Editing
S Split selected items at cursor Win mac Linux
DEL Delete selected items Win mac Linux
CTRL+Z Undo Win Linux
+Z Undo mac
CTRL+⇧ Shift+Z Redo Win Linux
+⇧ Shift+Z Redo mac
CTRL+D Duplicate selected items Win Linux
+D Duplicate selected items mac
CTRL+A Select all items Win Linux
+A Select all items mac
Tracks
CTRL+T Insert new track Win Linux
+T Insert new track mac
M Toggle mute on selected track Win mac Linux
S Toggle solo on selected track (in track header) Win mac Linux
File
CTRL+S Save project Win Linux
+S Save project mac
CTRL+⇧ Shift+S Save project as Win Linux
+⇧ Shift+S Save project as mac