Can the MIT license be changed?

Question

Licenses for software and other works

The library, significantly rewritten, is based on the source code under the MIT license.
Can I change the license for a new library?
Thank you.

Answer 1

IANAL, TINLA.
> the source code is taken under the MIT license
I don't think that the answer will depend much on that, but nevertheless, under which one? [0]
> substantially rewritten
Doesn't matter.
> Can I change the license for a new library?
The most common of the so-called. The “MIT license”, called the Expat license, quite directly and unequivocally informs you that you are returned, including the right to sublicense the work:
“Permission is hereby granted ... 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" - [1] (emphasis mine).
Which, to some degree of plausibility, could be stated in Russian as:
“Permission is hereby given ... to use the SOFTWARE without restrictions, including without limitation the right to use for its intended purpose, reproduce, modify, connect, publish, distribute, sublicense and / or sell copies of the SOFTWARE” (my translation)
This essentially means that you have the right to transfer the work to others under the terms of your own license agreement.
Just do not forget to comply with yourself, and oblige your licensees to comply with the conditions under which all this is returned to you; they are set out one paragraph below:
"The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software."
Which means roughly:
"The above proprietary copyright notice and this permission notice must be included in all copies or substantial portions of the SOFTWARE."
At the same time, even if the agreement that you called the “MIT license” (or any other license in general) does not explicitly mention sublicensing, this should not yet be unambiguously interpreted as if this right is not returned to you. You just need to study the issue in more detail.
[0] https://fedoraproject.org/wiki/Licensing:MIT
[1] https://directory.fsf.org/wiki/License:Expat