FOSSwire » Midori – a Lightweight WebKit Browser for Linux
There are a couple of others (Konqueror, Epiphany), but the primary open source browser that you’re likely to be using on Linux is Firefox.
Now don’t get me wrong, Firefox is great for a lot of things. It is endlessly customisable and has ubiquitous support from website developers. It does have disadvantages too, however, including not exactly being the quickest beast out there.
WebKit is an open source browser engine (the code that does the heavy lifting inside your browser) that Apple made for its Safari browser. It is derived from the KHTML engine that was developed for Konqueror, but was reworked quite a bit by Apple and now various other third parties.