The GPLv3 and AGPLv3 are quite similar. They differ only by
- an additional requirement in the AGPL that makes a network service powered by a modified AGPL-licensed work operates like conveyance of the work (and therefore imposes source-sharing requirements)
- an additional permission in the AGPL that GPLv3-licensed work can be included in an AGPL-licensed work
The FSF has put much work into determining the GPL compatibility of various licenses, but no obvious work into compatibility for the AGPL. (This makes sense, since the GPL is much more popular, of course.)
- Can I safely assume that any given license's compatibility with the GPL and its compatibility with the AGPL will be the same?
- If not, under what circumstances would they differ?
Within the GPL family of licenses, GPL compatibility and AGPL compatibility are identical:
Each place that the matrix states GPLv3, the same statement about compatibility is true for AGPLv3 as well.
This is likely due to the explicit coordination in the section 13 of the AGPL and GPLv3 itself. In any case, I am interested in how other licenses have differing or identical compatibility between the GPLv3 and AGPLv3.