Continuing my reading of ASP.NET I came across this description of one of the benefits of these controls over the old HTML Server Controls: "ASP.NET server controls automatically detect the client browser requesting the page and render the controls based on the browser's capabilities.".

That sounds most useful, for sure. But I got to wondering how it can accomplish this.

Does anyone know HOW this is achieved?
It occurs to me that doing this well for any of the possible requesting browsers requires intimate 'knowledge' of that specific browser. While I can easily see there being no problem as regards MS' Internet Explorer, I wonder how NetScape or Opera or any other browser can be adequately 'represented' under this scenario.

It seems to me that this is something that we should be concerned about. Issues surrounding this may include:
1) Who writes the code responsible for doing the best rendering job for each browser?
--- Does MS write it for IE, AOL for NetScape, etc.?
2) How does it get installed and maintained on our systems?
3) Can the code responsible be maintained separately for each independent browser?
---a) Can I identify separately the version/level/build of the subject code for each of IE, NetScape, Opera, etc.?
---b) Can I see which version of the corresponding browser each is designed for?
---c) Can I have separate versions (of this 'best-render-code') for different versions of each possible browser?
---d) Can I add/update/remove separate versions of the 'best-render-code' as I see fit?
4) Does this create a nightmare for maintenance?
--- Is this another means to push other browsers out of the picture?

While I can see how nice the concept described by the description (quoted above) is, it looks like it could come at significant cost in terms of future flexibility to choose a browser of preference.

I think that knowing how this is implemented would be useful information.

If you know, I'd appreciate enlightenment.
Thanks