Module System
Introduction to modules through a ModuleSystemTutorial.
ModulesForTheories: Using modules and records to capture mathematical theories.
RecordsNotModules: Why you shouldn't use the module system at all, and use dependent records instead.
ModulesNotRecords: Why the previous line does not always stand.
ProofTermsConsideredHarmful: Why using dependent records can be difficult, and sometimes inadvisable.
TypeClasses (experimental in Coq 8.2) can also be used to capture mathematical theories, like in IsabelleTheoremProver. They use parameterized dependent records internally.