Open source licenses

Here below the list of the main open source licenses broadly used in academia and business.

Before downloading or sharing open source software you should consider that license compatibility between open source licenses is not always granted.
This means that combining code released under different licenses may result, without the direct permission of the copyright holder, in a code which cannot be legally distributed.
 
 
MIT
The MIT license is a very short and permissive license for users. The software can be used for any application including integration into commercial software (e.g. proprietary software) as long as the original copyright holder is cited in the re-distributed software. Software is provided without warranty and the software author/owner cannot be held liable for damages (as far as permitted by applicable law).
 
BSD
The BSD license is also a very short and permissive license for users. The software can be used for any application including integration into commercial software (e.g. proprietary software) as long as the original copyright holder is cited in the re-distributed software. Use of trademarks from original licensors is expressly prohibited. Software is provided without warranty and the software author/owner cannot be held liable for damages (as far as permitted by applicable law).
 
Apache 2.0
Apache is also considered a permissive license for users. The software can be used for any application including integration into commercial software (e.g. proprietary software) as long as the original copyright holder is cited in the re-distributed software. The license provides an express grant of a license under patents, which the contributors may have on the software. Software is provided without warranty and the software author/owner cannot be held liable for damages (as far as permitted by applicable law).
 
GPL
GPL is a so-called “copyleft “ license. This means that anyone who wants to re-distribute the code in a modified or unmodified form shall also  share the source code of the original software as well as the source code of his/her own modifications, under the same license terms. For this reason GPL license is also called viral. The license provides an express grant of a license under patents, which the contributors may have on the software.
Commercial use of GPL code is allowed as long as the source code is also provided to end users.
 
LGPL
Based on the original GPL license the Lesser GPL software license is applied to software libraries and requires sharing, under the same terms, the source code of any modified or unmodified version of the library, which the user wants to further distribute. Integration and distribution of proprietary software with different license terms in conjunction with LGPL software is in principle allowed provided that the library is just linked to the main application.
 
AGPL
Affero GPL is a very strong copyleft license that requires anyone distributing or using server applications using AGPL protected software to made available the source code to any network user. This license is also considered viral (see above “GPL”). The license provides an express grant of a license under patents, which the contributors may have on the software. Commercial use of AGPL code is allowed as long as the source code is also provided to end users.