The Opera browser is now totally free. Opera started out as one of the few commercial competitors to Microsoft and Netscape’s free browsers. They later came out with an ad-supported version that you could use for free if you didn’t want to pay extra to get rid of the ads, and now they have finally eliminated the ads and made it entirely free.
This has apparently been out there for a while, but it doesn’t seem to have gotten much hype. Opera has long been considered one of the fastest and most standards compliant browsers available, but it’s commercial beginnings may have hurt its acceptance. It has its quirks, but it’s a pretty good browser that also includes a decent mail client and RSS reader, and all within an installed size that’s barely a third the size of Firefox.