You are discounting the ubiquity of both Flash and Java. I could easily imagine you not taking seriously other plugins like Shockwave, Unity, etc., but if your argument is based on what a given person will have installed on their machine by default, you've still got Flash and Java.
That's not perfect, but it definitely works in a pinch. Just add an opening angle bracket before br. I couldn't get the formatting correct
C'est magnifique, mais ce n'est pas l'Informatique. -- Bosquet [on seeing the IBM 4341]