Supersymmetry breaking and stability in string vacua

We review some aspects of the dramatic consequences supersymmetry breaking on string vacua. In particular, we focus issue vacuum stability in ten-dimensional models with broken, or without, supersymmetry, whose perturbative spectra are free tachyons. After formulating at stake, introduce their unified low-energy effective description and present a number solutions to classical equations motion. addition, generalization previous no-go results for de Sitter vacua warped flux compactifications. Then analyze quantum these vacua, studying linearized field fluctuations bubble nucleation. Then, describe how resulting instabilities can be framed terms brane dynamics, examining particular interactions, back-reacted geometries commenting brane-world construction along lines recent proposal. providing summary, conclude perspectives possible future developments.