Over the last 11 years, we have built and continue to build an extremely extensive user agent parser. We offer easy access to it via our User Agent API. The API also provides useful information such as the latest browser and operating system version numbers.
To get an idea of all the different software, operating systems, hardware & software types, operating platforms (and more!) that it is capable of detecting, you can browse our user agents section.
On the homepage of whatismybrowser.com we show a read out of heaps of other stuff which your browser can detect. We've made the Javascript that we use for this freely available, so you can use it on your own site now too.