I've not tried any of them myself, but the list in the article from http://news.ycombinator.com/item?id=1134301 http://news.ycombinator.com/item?id=1134301 seem

I've not tried any of them myself, but the list in the article from http://news.ycombinator.com/item?id=1134301 http://news.ycombinator.com/item?id=1134301 seemed quite sensible.