These are both makefile-based solutions, and "make getlinklibs" is a better ways to snarf the variables. We could easily write a pkgconfig file for PETSc. Some people would like that, but pkgconfig doesn't really care about supporting multiple installs (different PETSC_ARCH). As I've suggested before, I think we should have a pure Python script that provides the information in a machine-readable way (listing library paths without "-Wl,-rpath," flags that may need to be adjusted if the user is not linking exactly the same way that PETSc was, correctly handle shared versus static linking, etc).