Browser & Feature Detection With PHP: Detector
Detector is an open source PHP library for detecting many things about the browsing environment of a user.
It can get the browser used and browser's HTML5-CSS3 capabilities, analyze whether it is mobile, tablet, desktop or a spider and other stuff like color depth, viewport dimensions, cookie support, etc.
The library can automatically adapt itself to new browsers, versions and devices using the unique
user-agent string of each browser. Simply, no need to update a browsers database.
Detector makes use of Modernizr to get the HTML5-CSS3 features and runs the majority of the tests only once per user for a faster usage.
It offers a very useful grouping feature which allows us to define groups of browsers (like Chrome and Safari as a WebKit group, etc.) to take "per-group actions" easier.