IMO, Opera is an OK browser. My biggest complaint is the ad boxes on the free version. I could just pay for it, but why would I when firefox is at least equally good?

If opera ever wants to get any real market share, they are going to have to release their browser free and without ads.

I don't think they need to open source it. It'd be nice, but its realy too much to ask. And besides, how many mozilla or firefox users here compiled from source?