This is the development version of the HAIL-CAESAR model.
The High-performance Architecture Independent LISFLOOD-CAESAR model
HAIL-CAESAR is a hydrodynamic, landscape evolution, cellular automaton model. In other words, it simulates hydrological and erosional processes in a river catchment, for the purposes of investigating flood-inundation, sediment transport and catchment evolution over a range of timescales from hours to thousands of years. (And potentially longer if you are really patient enough...)
The model is derived from the CAESAR-Lisflood model, which is a C#/.NET Windows-based implementation of the model, with a very useful GUI. You may find much of the documentation and discussion for CAESAR-Lisflood relevant for using HAIL-CAESAR, but remember there are small differences at present, so treat the documentation here as the canonical source.
HAIL-CAESAR doesn't have a GUI - the model is run from scripts or from typing commands at the command line/terminal. The model runs and writes output directly to files on disk. You then have to process these output files yourself to view the model output subsequently.
Why is it called HAIL-CAESAR?
The original CAESAR Model stood for Cellular Automaton Evolutionary Slope and River model. It was developed by Tom Coulthard and was originally written in the C programming language. Later it was ported to the C# programming language and developed a GUI and you can watch the flood simulation update in real time on screen. Later still (2013), it was coupled with a flood inundation model, LISFLOOD-FP, which replaced the existing non-hydrodynamic flow routing model in CAESAR. In 2014-2016, it was translated into C++ to facilitate an OpenMP parallelisation of the model, so that it could be compiled and run on different computing services such as clusters and HPC, which are usually linux-based. I called it the High Performance Architecture Independent Lisflood CAESAR model, because everybody loves a good project acronym...