tinywallet: license

[teknico]

For the wallet user interface, the tinywallet package uses the Qt toolkit via the Riverbank PyQt5 bindings. PyQt5 is under the GPLv3 license and tinywallet is arguably a derivative work, therefore it cannot be under the ISC license, but must be under GPLv3 too.

(The decred package only has MIT/Apache/BSD-licensed dependencies and may stay under ISC).

If the GPLv3 license is too restrictive, an alternative would be to use PySide2 instead of PyQt5. PySide2 is under the less restrictive LGPLv3 license, same as Qt itself. The tinywallet license should then be LGPLv3 too.

PySide2 is part of Qt itself (managed by the "Qt for Python" project) and its documentation says:

"One of the goals of PySide2 is to be API compatible with PyQt5, with certain exceptions."

Hopefully the migration will be fairly painless.