The checkpoint file output formats offer great flexibility when visualizing the data. The visualization program does not have to know the details of how the file was written; rather it can query the file to find the number of dimensions, block sizes, variable data etc that it needs to visualize the data. IDL routines for reading HDF5 and PnetCDF formats are provided in tools/fidlr3/. These can be used interactively though the IDL command line (see Chp:FLASH IDL Routines (fidlr)). In addition, ViSit version 10.0 and higher (see Sec:visit) can natively read FLASH4 HDF5 output files by using the command line option -assume_format FLASH.