We can consider an app or module as Open Source if it have following aspects.Before use any of the opensource code or before using any opensource product you must know about its License and Details of Open Source i.e when you are trying Server installation in odoo and using different apps.
1. Publicly Accessible.
2. Modify and Distribute
3. Source code is Released under a License
4. Collaborative Efforts
5. Free
What is Open Source?
Open source doesn't just mean access to the source code. The distribution terms of open-source software must comply with the following criteria:
1. Free Redistribution
2. Source Code
3. Derived Works
4. Integrity of The Author's Source Code
5. Distribution of License
What is Open Source License?
Open-source license allows for a software product to be shared in certain ways, or for some types of collaborative research or development.
1. Permissive
2. CopyLeft
Permissive Open Source License
Several Example of Permissive Open Source License are as following:
1. FSF
2. MIT
3. Apache2.0
4. BSD
5. Python License
6. PSFL (FSF, OSI, DFSG, GPL)
7. Anything Goes( More Useful for Developer)
Copyleft License
1. Require Copyright
2. Copyleft exists within the rules of copyright
3. More Useful For Users
What is Copyright?
Copyright is a law that restricts the right to use, modify, and share creative works without the permission of the copyright holder.
No registration is required. By default, all rights are reserved. That means no one can republish, perform, or modify a work without permission from the author. This permission is a "license" and may come with certain conditions.
Top Open Source License
Top Open Source License are as following:
1. Apache 1.1 and 2.0 (patent Protection)
2. MIT (Anything)
3. BSD
4. GPL
5. GNU
6. CDDL
GNU (GENERAL PUBLIC LICENSE)
1. LGPL: you can link against and don't have to release source code as long as you don't modify the library itself.
2. GPL: you have to release source code if you link against and distribute the binary, but don't if you just provide a service.
3. AGPL: you have to allow the source to be downloaded even if you never distribute the binary but do provide a service