In my opinion, Opera seems to be the fastest browser for Windows applications.

我认为，对Windows应用程序而言，Opera是速度最快的浏览器。

There are obviously some security concerns to be considered when you run a service like this on your Windows, Mac, or Linux machine, though Opera obviously argues that Unite is secure.

尽管Opera认为Unite是安全的，但是当你在Windows，Mac或者Linux机器上运行某项服务时，你显然会有安全方面的一些顾虑。