Meaning of MIT license

Question

Suppose I use this ActionScript API released under MIT license to build a software: http://www.cove.org/ape/docs/api/

1. Can I sell that software?
2. Do I need to give the source code of my software away?
3. Is anyone receiving my software permitted to resell the software?

Answer 1

1. You can sell the software.
2. No, you are not compelled to provide source code.
3. Anyone who receives source code may do as the license permits. This does not extend to binary distributions.

Read the MIT license. Read the whole thing and understand it. It was meant to be read by ordinary people, unlike other licenses that are very complex:

Copyright (c) year copyright holders

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Answer 2

According to "Understanding Open Source and Free Software Licensing" by By Andrew M. St. Laurent:

These licenses, as applied to the original licensed code, allow that code to be used in proprietary software and do not require that open source versions of the code be dis- tributed. Code created under these licenses, or derived from such code, may go “closed” and developments can be made under that proprietary license, which are lost to the open source community. For the same reason, however, these licenses are very flexible and compatible with almost every form of open source license.

Answer 3

As always, consult a lawyer. If this library is released strictly using the MIT license then:

(i) Yes, you can sell your software provided you include the MIT license as part of your product. (ii) No, you don't have to share your code with the community but it would be nice. (iii) Yes, reselling is permitted.

MIT License:

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.