A Semantic Compiler constructs software from authorized source commitments. It elaborates a semantic abstract syntax tree, admits a checked contract, lowers its control description, and realizes an application together with its required bindings and execution support. The Semantic Control Layer (SCL) is the logical control discipline throughout this chain; it may be implemented in generated code, dedicated infrastructure, or both. Models propose interpretations and artifacts but do not grant authority. A bounded serial core is specified with typed candidates, protected evidence, persistent semantic state, operation-specific context, technical resource bounds, and mediated effects. Frontend outcomes distinguish between acceptance, material ambiguity, inconsistency, unsupported semantics, and inconclusive checking. Required sources are resolved from an independently authorized inventory and verifier justifications terminate at explicit trusted roots. History-bound evidence and property-preserving representations connect revision, context construction, and dispatch. The intender retains authority over material commitments while delegating technical realization within a checked contract to the Semantic Compiler.