  Topological constraint theory has become an increasingly popular tool to
predict the compositional dependence of glass properties or pinpoint promising
compositions with tailored functionalities. This approach reduces complex
disordered networks into simpler mechanical trusses. Thereby, topological
constraint theory captures the important atomic topology that controls
macroscopic properties while filtering out less relevant second-order
structural details. As such, topological constraint theory can be used to
decode the genome of glass, that is, to identify and decipher how the basic
structural building blocks of glasses control their engineering properties---in
the same way as the human genome offers information that serves as a blueprint
for an individual's growth and development. Thanks to its elegance and
simplicity, topological constraint theory has enabled the development of
various physics-based models that can analytically predict various properties
of glass. In this Chapter, I introduce some general background in glass
science, concepts of atomic rigidity, and topological constraint theory. The
topological constraints enumeration scheme is presented for various
archetypical glasses and is used to understand the origin of their
glass-forming ability. Finally, various topological models enabling the
prediction of glass properties are reviewed, with a focus on hardness, fracture
toughness, viscosity, fragility, glass transition temperature, and dissolution
kinetics.
