What's the earliest version of Internet Explorer which can play Unity webplayer content?

What's the earliest version of Internet Explorer which can play Unity webplayer content?

I know that early versions of IE usually come hand-in-hand with old PCs which may not be up to spec to play unity content properly, but someimtes clients specify (or request) that their content must work on certain versions of IE.

The client in this case has said it must work on IE 5.5 or later.

I would also be interested if anyone has the correct information about which earliest versions of the other major browsers are supported (Safari, Firefox, Opera, etc).

(asking nicely for input from any UT engineers on this one please, as I can't see any publicly available information which provides a conclusive answer to this, and it is information that I need in order to help secure a job from a client!)

In our web server logs, when searching for requests to any of our .unity3d files, and cutting out only the User-Agent part, I get the following browsers matched:

# of users  Browser ID
------------------------
1           MSIE 5.0
a lot       MSIE 6.0-8.0
a few       Firefox 2.0.0 (.12-.20)
a lot       Firefox 3.0-3.6
a few       Opera 9.26
a lot       Opera 9.60-9.64
a lot       Opera 9.80 (ver. 10.00-10.51)
a few       Safari 3.1.2
a lot       Safari 3.2.x and 4.0.x
a few       Chrome 1.0.154.x
a lot       Chrome 2.0 - 5.0

In addition, our own testing has shown that Opera 8 is not really compatible, while Opera 9 and later should be working mostly fine. Earlier Chrome builds had some issues, but I can't remember if this has been fixed in Chrome or in Unity (if it's the latter, it should work with earlier versions now). Firefox 2 should work fine.

As for MSIE, you can see that we at least have not had any hits from MSIE 5.5, but one browser claiming to be MSIE 5.0 (although that can be spoofed - made perhaps even more likely that the hit was from a Chinese leech site). We haven't tested any of our games or solutions with anything prior to MSIE 6, so I can't say for sure.

If this is important, you might want to either have your client supply you with testing machines, or you could try something like this (disclaimer: not tested) to install multiple versions of MSIE on a Windows PC.

IE player is an activex control and i am sure that it works on IE6 but should not have any problem with 5.5. for opera you should see what IE version does it use. i used unity with firefox 2.x and 3.x but i don't know much about it.