The following list was compiled by IEA Wind Task 36 Forecasting for Wind Energy.
If you are new to the GRIB format, here are a few resources:
Each GRIB record contains the data and the meta data for its description, including information on the horizontal grid. Unlike netCDF the grid must not be contained in a file, only a description of the grid.
An important concept of GRIB is that the variables don't have names. They are identified by numbers. In GRIB2 it is a triple for discipline, category and parameter number. All tools show variable names. However, they are given via tables used by the software. This means that different tools may show you different variable names for exactly the same GRIB record.
The Wikipedia page is a good start, with many resources for many different software packages: https://en.wikipedia.org/wiki/GRIB
A very popular tool is wgrib or wgrib2. Some information is given at https://www.cpc.ncep.noaa.gov/products/wesley/
Another tool are the Climate Data Operators cdo: https://code.mpimet.mpg.de/projects/cdo/. They use eccodes or parts of it to read GRIB. With cdo you can easily convert GRIB to other formats e.g. netCDF (though you must be careful and you should check - if possible!)
At DWD we use ECMWF's ecCodes software to read GRIB. The link is https://confluence.ecmwf.int/display/ECC/ecCodes+Home which also has references to WMO pages.
To work with GRIBs I recommend the grib_api-tools which are part of ecCodes.
Status: 29 January 2020, Helmut Frank (DWD), Anton Kaifel (ZSW), Sebastian Haglund El Gaidi (Greenlytics)