All, Matthew (cc'ed) and I are going to start working on an AMGx interface in PETSc, PCAMGX, and I suggested that he may want to think about moving the core AMG PC code into PETSC as a built-in PC. 1) We would have to decide of we want the maintenance burden of moving the whole thing in, but we will probably start with a 3rd party library unless this move starts looking like a really good idea. We have not started to really dig into this. 2) NVIDIA's lawyers have some thoughts that we will need to address even with a 3rd party library (I know Hypre has this license notification and LLNL seems happy with what we did). First, Mathew says that this process "can open the door to us helping with PETSc more generally." I will just quote the rest of Mathews' message: Thanks, Mark *I can see you don't add license notifications to the headers of the source files, but this tends to be the approach we take for copyright. I'm also not sure there is a very good alternative?* *Instead of the monolithic copying of the full BSD-2 license with the NVIDIA copyright (which I appreciate might not be desirable), would it be a suitable compromise if we used the SPDX identifier, which looks like:* *// Copyright (c) 1991-2021, NVIDIA. All rights reserved.* *// Copyright (c) 1991-2021, UChicago Argonne, LLC and the PETSc Development Team. All rights reserved.* *// SPDX-License-Identifier: BSD-2-clause* *This would be for the main source files that we make any significant contributions to or author. I would be interested to hear your thoughts / ideas on this.*