nLab
Loc

$\mathrm{Loc}$ is the category whose objects are locales and whose morphisms are continuous maps between locales. By definition, this means that $\mathrm{Loc}$ is the opposite category of Frm, the category of frames.

$\mathrm{Loc}$ is used as a substitute for Top if one wishes to do topology with locales instead of standard topological spaces.

category: category