GPLv3 / LGPLv3 license?

[WofWca]

I was thinking about switching to GPL-3.0-or-later or at least to LGPL-3.0-or-later. Do you think it would be good?

[drewnoakes]

Changing the license likely requires contacting every prior contributor and gaining their agreement.

What is the reason you'd like to change the license?

[WofWca]

Actually we don't have to contact every contributor as long as we also keep the original notice.

The reason I want to switch to GPL is simply because I think it's better for free software. Plain GPL disallows incorporating it into proprietary software altogether, LGPL requires publishing the source code of the library if any changes were made to it.

[drewnoakes]

Actually we don't have to contact every contributor as long as we also keep the original notice

Does this mean the old license would still apply in perpetuity? If so, what does the project gain by having two licenses?

[WofWca]

As far as I understand, MIT should only apply to the version with no GPL changes in it, which can only be extracted by looking at git log, So it should make (L)GPL the only practically applicable license. Here's an aricle, see section 2.2.