osu-deploy 
Deploy task for osu!lazer.
This is what creates installable copies of lazer.
Made for internal use; as such documentation is not provided. YMMV.
Licence
The osu! client code, framework, and tools are licensed under the MIT licence. Please see the licence file for more information. tl;dr you can do whatever you want as long as you include the original copyright and license notice in any copy of the software/source.
Please note that this does not cover the usage of the "osu!" or "ppy" branding in any software, resources, advertising or promotion, as this is protected by trademark law.