AGMG is now under a closed-source license, meaning that results obtained with this solver is not freely reproducible by others. Its use is therefore discouraged. As of version 2.3, the DUNE AMG parts are competitive, so there is a free and open alternative.
These files are not actively maintained. They may not compile, run properly nor produce sensible results. In the future they may be promoted into proper examples or unit tests, or deleted.