I've found a software library I want to use in my closed source commercial project. It has new BSD license . Can I do it?
Yes. You can use BSD-licensed projects in closed-source, commercial projects. You must include the original copyright and license.
The BSD License allows proprietary use and allows the software released under the license to be incorporated into proprietary products. Works based on the material may be released under a proprietary license as closed source software, allowing usual commercial usages under.