How to submit a new plugin? what are the requirements? source is enough or compiled binaries ?
Source is enough if it’s readily pullable from github and uses a reasonable makefile. look here: https://github.com/VCVRack/library.
so shall I just add a submodule and open a PR ? it’s open source
You have to open a Github issue with the name of your plugin and a link to its repository. Did you upload it to github ?
All of your questions are answered in the README. https://github.com/VCVRack/library#adding-your-plugin-to-the-vcv-library-for-open-source-plugins