Linux protocol finishing

Open source:
free and open
Linux
GPL agreement : 1. No matter what form the software is released in, the source code must be attached at the same time.
2. Companies or individuals that develop or maintain software developed in accordance with the GPL agreement can charge users a certain service fee. But there is an old saying-the complete source code of the software must be provided free of charge, and the source code must not be bundled with the service or bundled in any disguised form.
LGPL agreement : GPL's open source agreement for class libraries: open source code can be sold commercially .
BSD agreement : 1. Freely used to modify the source code: open source or proprietary in the release:
2. If the released product contains source code: the source code must The BSD protocol with the original code
3. If you send a class library, the copyright of the class library also needs to include the BSD protocol
4. It can be commercialized, but the author and organization of the source open source code cannot be used to promote the
APACHE protocol :
1. Permanent Rights
2. Global rights
3. Authorization is free and copyright-free
4. Anyone can obtain authorization
5. Once authorized, no one can cancel