Tested with Python 2.7.1 / Linux 2.6.33.2 / Opera 10.63. Build 6450 for Linux

class Opera(UnixBrowser) shows:
raise_opts = ["", "-raise"]

"-raise" is not a valid command line option for Opera.

This causes all webbrowser open methods (that use autoraise=True by default) to not work correclty with Opera (webbrowser.open returns True, but Opera does not open, etc).

The raise options should probably be changed to:
raise_opts = ["-noraise", ""]

Opera - UNIX Command Line Options: http://www.opera.com/docs/switches/#unix

According to the linked doc, Opera has '-noraise' but not '-raise' as a command line option (to not raise window when receiving remote commands).

It does have '"raise()"' (with quotes and parens, but not "noraise()") as a remote command following the '-remote' command line option to be sent to another Opera window. I suspect this as the reason for the apparently invalid 
raise_opts = ["", "-raise"]

From the usage of raise_opts in UnixBrowser._invoke, which concatenates one of the entries, if not "", to self.name, I am pretty sure the command line form is what is wanted and that the proposed
raise_opts = ["-noraise", ""]
is correct.

Attached patch also removes a few blank lines to make entries for different browsers consistent.

Georg, if you agree, I will commit the change and backport.

By all means.

3.2,3.1,2.7: r87553, r87554, r87555