# Next-level full-stack development ## Write your app once — deploy on Web, Android, iOS ## Unique multi-tier architecture: client and server in a single program ## Type-safe from database to UI — catch errors before they happen ## Runs natively in WebAssembly (with JavaScript fallback) [Get started now\!](/tuto/latest/basics.html) - - - - - - - - - ## Eliom ### Client and server code that compile together Eliom lets you write **client and server code in the same file, and as a single program**. The compiler checks that they stay consistent — **no more broken APIs**\! A single codebase compiles to a **Web app** and to **mobile apps** for iOS and Android. ## Js\_of\_ocaml / Wasm\_of\_ocaml ### Your OCaml code, running in the browser at near-native speed Compile any OCaml program to **JavaScript** or **WebAssembly**. WASM delivers near-native performance; JS ensures compatibility with all browsers. Works directly from OCaml bytecode — **use any OCaml library without recompiling**. Seamless interop with JavaScript libraries. ```ocaml let fib num = let rec aux num prec2 prec = if num = 0 then prec else aux (num - 1) prec (prec + prec2) in aux num 1 1 ``` ```javascript function fib(num) {var num$0=num,prec2=1,prec=1; for(;;) {if(0 === num$0)return prec; var prec$0=prec + prec2 | 0, num$1=num$0 - 1 | 0, num$0=num$1, prec2=prec, prec=prec$0; continue}} ``` ```javascript function(d){var b=d,c=1,a=1;for(;;){if(0===b)return a;var b=b-1|0,e=a+c|0,c=a,a=e;continue}}; ``` ➔ ➔ ## Main projects ### Js\_of\_ocaml Compile OCaml to JS and WebAssembly. Run in any browser. ### Eliom Write client and server as one program. Deploy to Web and mobile. ### Server Production-ready Web server with native OCaml integration. ### Lwt Concurrent programming made simple — no callback hell. ### Tyxml Type-safe HTML/SVG generation. Invalid markup won't compile. ### Ocsigen Toolkit Ready-to-use UI widgets for Web and mobile apps. ### Start Complete starter app with users, notifications, and mobile support. ## From the blog [More posts →](/blog/)