JSCoverage is a tool that measures code coverage for JavaScript programs. Code coverage statistics show which lines of a program have been executed (and which have been missed). This information is useful for constructing comprehensive test suites (for which it is often called test coverage). JSCoverage works by instrumenting the JavaScript code used in web pages. Code coverage statistics are collected while the instrumented JavaScript code is executed in a web browser. JSCoverage works with any modern standards-compliant web browser - including Internet Explorer (IE 6 and IE 7), Firefox (FF 2 and FF 3), Opera, and Safari - on Windows and Linux.