diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -202,10 +202,11 @@ Contributions are welcome. Add links through pull requests ([guidelines](CONTRIB
 
 *Read or contribute to the code behind major regex implementations.*
 
-- [V8: Irregexp](https://github.com/v8/v8/tree/main/src/regexp) - JavaScript `RegExp` engine used by Chrome, etc.
+- [V8: Irregexp](https://github.com/v8/v8/tree/main/src/regexp) - JavaScript `RegExp` engine used by Chrome, Edge, [Firefox](https://hacks.mozilla.org/2020/06/a-new-regexp-engine-in-spidermonkey/), etc.
+- [JavaScriptCore: RegExp](https://github.com/WebKit/WebKit/blob/main/Source/JavaScriptCore/runtime/RegExp.cpp) - JavaScript `RegExp` engine used by Safari.
 - [Boost.Regex](https://github.com/boostorg/regex) - Popular C++ regex library.
 - [Hyperscan](https://github.com/intel/hyperscan) - Intel's high-performance library, used for [DPI](https://en.wikipedia.org/wiki/Deep_packet_inspection).
-- [ICU](https://github.com/unicode-org/icu/blob/main/icu4c/source/i18n/unicode/regex.h) - Unicode org's package with full Unicode support.
+- [ICU](https://github.com/unicode-org/icu/blob/main/icu4c/source/i18n/regexcmp.cpp) - Unicode org's package with full Unicode support.
 - [Java: java.util.regex](https://github.com/openjdk/jdk/tree/master/src/java.base/share/classes/java/util/regex) - JDK standard regexes.
 - [.NET: System.Text.RegularExpressions](https://github.com/dotnet/runtime/tree/main/src/libraries/System.Text.RegularExpressions) - Shared by all .NET languages (C#, VB, etc.).
 - [Onigmo](https://github.com/k-takata/Onigmo) - Forked and extended from Oniguruma. Default regex library of Ruby 2.0+.