The book Finite Volume Methods for
Hyperbolic Problems contains detailed descriptions of the algorithms
used in Clawpack, and many examples with associated Clawpack code.
Some of these examples are available on the
Clawpack 4.3 website but have not yet been converted.
SharpClaw, Semi-discrete High-order AccuRate Package for
Conservation Laws, David Ketcheson's generalization of his WENOClaw package
using WENO reconstruction and Runge-Kutta timestepping.
PyClaw is a Python version of Clawpack that includes the PetClaw,
a parallel version of Clawpack, using PETSc.
a parallel, multi-block adaptive code based on Clawpack and
the parallel, scalable octree infrastruture in p4est.