Eclipse Tycho is a Maven-based build tool for Eclipse plug-ins, OSGi bundles, features, p2 repositories, and RCP applications. It integrates with the Eclipse p2 provisioning system to resolve dependencies, generate metadata, and package artifacts. The architecture is a collection of Maven plugins (mojos) that extend the standard Maven lifecycle with OSGi-specific phases. Key entry points include the compiler plugin (tycho-compiler-plugin), packaging plugin (tycho-packaging-plugin), p2 metadata plugin (tycho-p2-plugin), surefire test runner (tycho-surefire), and version management plugin (tycho-versions-plugin). Data flows involve reading OSGi manifests, feature.xml, product files, and target definitions, resolving dependencies from p2 repositories and Maven artifacts, compiling with JDT, generating p2 metadata, and producing deployable artifacts. External dependencies include Eclipse Equinox/p2, bnd, ASM, JDT, and Maven core. The codebase is large and mature, with extensive integration tests and demo projects, but contains some copied p2 internals and deprecated APIs.