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docs/i18n_support.md

+# ECMAScript 402
+
+V8 optionally implements the [ECMAScript 402](http://www.ecma-international.org/ecma-402/1.0/) API. The API is enabled by default, but can be turned off at compile time.
+
+
+## Prerequisites
+
+The i18n implementation adds a dependency on ICU. If you run
+
+```
+make dependencies
+```
+
+a suitable version of ICU is checked out into `third_party/icu`.
+
+
+### Alternative ICU checkout
+
+You can check out the ICU sources at a different location and define the gyp variable `icu_gyp_path` to point at the `icu.gyp` file.
+
+
+### System ICU
+
+Last but not least, you can compile V8 against a version of ICU installed in your system. To do so, specify the gyp variable `use_system_icu=1`. If you also have `want_separate_host_toolset` enabled, the bundled ICU will still be compiled to generate the V8 snapshot. The system ICU will only be used for the target architecture.
+
+
+## Embedding V8
+
+If you embed V8 in your application, but your application itself doesn't use ICU, you will need to initialize ICU before calling into V8 by executing:
+
+```
+v8::V8::InitializeICU();
+```
+
+It is safe to invoke this method if ICU was not compiled in, then it does nothing.
+
+
+## Compiling without i18n support
+
+To build V8 without i18n support use
+
+```
+make i18nsupport=off native
+```