Reports a common JavaScript pattern for detecting the browser or operating system in which the script is run. In addition to pointing out non-portable constructs, these platform detection patterns are often incomplete and easily fooled. For most cases, detection of individual environment features is preferable to attempting to detect the entire platform.

Patterns detected include:

document.all
document.layers
navigator.userAgent
navigator.oscpu
navigator.appName
navigator.appCodeName
navigator.platform