There should be no Alt-bound keyboard shortcuts on the mac ever - it is used on international keyboards as the compose key (for a long time, we didn't know it, but Norwegian and French users could not type } or { in NetBeans - kind of limits the usefuless of a Java IDE).

All standard shortcuts should be bound with wildcard keys - e.g., in the layer, not AS-P for Alt-Shift-P, but OS-P, which will map to Alt-Shift-P on PC and Ctrl-Shift-P on mac. For Ctrl/Command, in the layer put DS-P instead of CS-P to bind conditionally to ctrl on PC and command on mac.

All Alt-bound keybindings in the IDE are specified with O so that they are rebound to Ctrl on mac, because they will interfere with typing in a lot of locales (the real way to think about it is "the mac does not have an Alt key" - it does but it is a composition key - you can't use it).

Any alt-bound keybinding on mac is a bug. If you use the logical syntax for keybindings, your app will always work intuitively on any platform.

Note that the mapping handling does skip key combinations that simply can't work on Mac - for example, Command-H and Command-Q are always consumed by the OS, so D-H and D-Q map to Ctrl-H and Ctrl-H, respectively, everywhere.

Source: NetBeans FAQ