/* Home — PAS, problem-first. README-driven. Globals from shared.jsx. */ const HomeDS = window.ZeroZ4JDesignSystem_f7e0ed; /* HERO — leads with the PROBLEM. No code, single balanced column + meta bar. */ function Hero() { return (
The Problem · Architectural impedance

Java Enterprise web development is drowning in translation layers.

Four languages, four paradigms, three copies of every model. A stack so fragmented that neither your engineers nor your AI coding agents can hold it in a single coherent view — and every layer is a place where cost, safety, and comprehension collapse.

See the Cost Why this was built
{[ ["Nature", "Pure-Java reference architecture"], ["Thesis", "Radical simplification is possible"], ["Author", "Franz Schöning · Enterprise AI Architect"], ["Source", github.com/fschoning/zeroz4j ↗]]. map(([k, v], i) =>
{k}
{v}
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); } /* AGITATE — the four mismatches from README §1. AI context collapse highlighted. */ function Agitate() { const pains = [ { t: "The database mismatch", b: "Domain models in Java are translated via SQL or JPA/Hibernate to map onto relational tables — creating dual-schema maintenance for a single idea." }, { t: "The network mismatch", b: "Java objects are serialized into text (JSON), sent over HTTP, and parsed back into JavaScript/TypeScript objects on the client. Every field crosses on faith." }, { t: "The UI mismatch", b: "JavaScript or TypeScript is required to mutate a browser DOM — fracturing the codebase's language ecosystem in the one place Java never reached." }, { t: "AI context collapse", b: "An AI coding agent must hold context across four languages and paradigms — SQL, Java, JSON, TS/JS. That load causes hallucinations, broken contracts, and security holes.", cyan: true }]; return (
The Cost

Every boundary is a place to bleed.

Modern enterprise web development is drowning in translation layers — massive friction for human developers, and catastrophic context collapse for AI coding agents.

{pains.map((p) =>

{p.t}

{p.b}

)}

Every translation layer breaks static analysis, prevents fearless refactoring, and forces the application to maintain three different models of the exact same data.

); } /* SOLUTION — one object model across every domain + real backend logic. README §2. */ function Solution() { const rows = [ { d: "Browser UI", conv: "TypeScript / React", z4: "Java → WebAssembly" }, { d: "Transport", conv: "JSON over REST/HTTP", z4: "Binary RPC over WebSocket" }, { d: "Server logic", conv: "Java + mapping layers", z4: "Java (Jakarta EE / CDI)" }, { d: "Persistence", conv: "SQL / JPA / Hibernate", z4: "Java object graph (EclipseStore)" }]; return (
The Solution

Impedance, eliminated.

No ORM. No JSON. No JavaScript. The translation layers aren't optimized — they're gone. One Java object runs from the button click to the stored byte, never re-encoded, never duplicated, never translated.

{/* Domain map: the same object model across every layer */}
{["Domain", "Conventional stack", "ZeroZ4j"].map((h, i) =>
{h}
)}
{rows.map((r, i) =>
{r.d}
{r.conv}
{r.z4}
)}
◆ Every ZeroZ4j column is the same language — and the same ChatMessage object, unchanged from browser to disk.
{/* Backend business logic — the object arrives exactly as sent */}

Business logic, no plumbing.

The server method receives the exact object the client sent — no controller, no deserialization, no mapping. Persist it or broadcast it as plain Java.

{cy("@ApplicationScoped")}{"\n"} {kw("public class")} ChatServiceImpl {kw("implements")} ChatService {"{"}{"\n"} {" "}{cy("@Inject")} EmbeddedStorageManager storage;{"\n\n"} {" "}{cy("@Override")}{"\n"} {" "}{kw("public")} {kw("void")} sendMessage(ChatMessage msg) {"{"}{"\n"} {" "}{cm("// the exact object sent from the client")}{"\n"} {" "}DataRoot root = (DataRoot) storage.root();{"\n"} {" "}root.getMessages().add(msg);{"\n"} {" "}storage.store(root.getMessages());{"\n"} {" "}{"}"}{"\n"} {"}"}

Because the stack is unified, AI coding agents can generate end-to-end features with near-perfect accuracy, and human developers can refactor from the database to the button-click with a single IDE command.

); } /* PILLARS — README §3 A/B/C */ function Pillars() { const cards = [ { i: "PILLAR.A", t: "Native object persistence", b: "EclipseStore bypasses the object-relational mismatch entirely — no UPDATE statements, no N+1 queries. The in-memory graph is explicitly saved; realtime UI updates can be implicit via @LiveSync." }, { i: "PILLAR.B", t: "Binary RPC + Project Loom", b: "REST and JSON are discarded for a custom binary protocol over persistent WebSockets. Virtual Threads absorb thousands of connections, so I/O threads never block during processing." }, { i: "PILLAR.C", t: "AOT compilation, zero DOM state", b: "TeaVM AOT and compile-time annotation processors avoid runtime reflection. Unlike Vaadin, ZeroZ4j keeps zero server-side DOM state — components live entirely in the client Wasm heap." }]; return (
Architectural pillars

Curated for concurrency and correctness.

{cards.map((c) =>
{c.b}
)}
Read the Docs Protocol spec →
); } function Home() { return ( ); } ReactDOM.createRoot(document.getElementById("root")).render();