▸ COSMO model
   in a nutshell:

an overview of the components that made up the whole Cosmo environment

▸ core
   documentation:

the "official" user guides (pdf) on all aspects (physics, dynamics, data assimilation, user guide, formats etc)

▸ other
   documentation:

COSMO Technical reports
the vertical coordinates system (2010)
the Model Output and Data Formats for I/O (2019)
the Feedback File Definition (2012).

▸ general technical
   description:

dynamics and numerics
physical parameterizations
data assimilation
initial and boundary conditions
external parameters
code and parallelization

▸ initialization:

Int2lm is the interpolator model that produced lateral boundaries from the global driving Models

▸ release notes:

release notes (of changes and additions) for each Int2lm and Cosmo version

▸ FLake:

the fresh-water lake model for Cosmo

▸ dev-oriented:

for sometime (~up to 2014), developers kept account on:
bug reports and their handling
model developments per workroup
brief history on new developments per release

▸ coding:

the GRIB Data Format used for the COSMO-Model System
the COSMO Coding Standards