What agent is this?

[fischermx]

I'm experimenting with my own log analyzer and I see this agent very often.

Netscape
5.0 (Macintosh; U; Intel Mac OS X; en) AppleWebKit/418 (KHTML, like Gecko) Safari/417.9.3

What exact browser is this?

[jdMorgan]

[developer.apple.com...]

Jim