Ciao is a logic-based, multi-paradigm programming language which has pioneered over the years many interesting language- and programming environment-related concepts. An example is the notion of programming languages as modular language-building tools rather than closed designs. Another is the idea of dynamic languages that can optionally and gradually offer formal guarantees, which is also a solution for the classic dichotomy between dynamic and static typing: Ciao has many dynamic features (e.g., dynamically typed, dynamic program modification) but includes an assertion language for (optionally) declaring program properties and powerful tools for static inference and static/dynamic checking of such assertions, testing, documentation, etc. We will provide a hands-on overview of these features, concentrating on the novel aspects, the motivations behind their design and implementation, their evolution over time, and, specially, their use. In particular, we will show how the system can be used not only as a programming tool and as a language design tool, but also as a general-purpose program analysis and verification tool, based on the technique of translating program semantics (ranging from source to bytecode, LLVM, or assembly) into Horn-clause representation, and idea which Ciao also introduced early on. Finally, we will present some recent work in areas such as scalability, incrementality, or static vs. dynamic costs, as well as some future plans and ideas.