Newyorkcoin Core is released under the terms of the MIT license. See COPYING for more information or see http://opensource.org/licenses/MIT.
Developers work in their own trees, then submit pull requests when they think their feature or bug fix is ready.
If it is a simple/trivial/non-controversial change, then one of the Newyorkcoin development team members simply pulls it.
If it is a more complicated or potentially controversial change, then the patch submitter will be asked to start a discussion (if they haven't already) on the mailing list.
The patch will be accepted if there is broad consensus that it is a good thing. Developers should expect to rework and resubmit patches if the code doesn't match the project's coding conventions (see doc/coding.md) or are controversial.
Testing and code review is the bottleneck for development; we get more pull requests than we can review and test on short notice. Please be patient and help out by testing other people's pull requests, and remember this is a security-critical project where any mistake might cost people lots of money.