CLAP is released under the industry standard MIT open-source license. You can read the entirety of the license here.
The MIT License means that you can use any part of the CLAP code in your software whether it is open source, closed source, free, or commercial, and do so without signing any licenses with a third party, joining any industry organizations, or paying any fees.
We chose the MIT license precisely because we think open licenses make thriving standards. If you are going to invest in a project as complicated as an Audio Plug-in or Host, you want to be sure that the very base of your software will be available to you in perpetuity, and the resulting software will be yours to do with as you see fit.
With proprietary licenses, where you don’t own the base software comprising a standard, your plug-ins or hosts exist under someone else’s terms, which are often unacceptably cumbersome. With ‘contagious’ open-source license (like GPL3), using the associated software requires your software to be open source.
But with CLAP (and other MIT licensed audio software), you are free to use the software without restriction.
In fact, the only requirement using the CLAP places on you is to make the CLAP license available somehow (an appendix in your manual, a scroll by on your about page, or so on).
When we surveyed other industries with healthy cross-industry standards, we found that most had made a choice similar to ours. Standards are available to all industry participants without a single owner or a constraining license.
But the major successful audio plug-in standards today deployed in the largest number of hosts and plug-ins are subject to proprietary licenses.
So while CLAP is not the first software in the audio industry to use an open license, we think the choice to make CLAP fully open and to allow you to express your creativity, build your business, run your educational program, or give away your software on your terms is a critically important feature.