seriously, who does that? 'msie5.0 mozilla', good times. 'like gecko' => msie trying to look like webkit, who tries to look like firefox. yeah, makes perfect sense. could anyone give an example of a modern application that checks against the user agent string?
Gmail. Google docs, every single page titled something demo, ... basically every other site. And it should die already. Browser vendors put up with it because there are thousands and thousands of sites that wouldn't work just because you have the wrong user-agent string and the web developer was incompetent. Great examples include Chrome's idiotic string[1] and Opera's version 9.80[2].
1. Discussed around.
2. http://dev.opera.com/articles/view/opera-ua-string-changes/
> Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.40 Safari/537.31
Its a sad situation.
I agree with "who does that" because I've never done UA sniffing so I had to look up the term "like Gecko" to even understand the context. As someone else has pointed out, that's for browsers that are not using the Gecko rendering engine. So essentially, everyone is trying to be "like Gecko" in one way or another.
I don't think this is aimed at fixing modern applications. It is aimed at much older ie 6-8 era code still on the web that has a bunch of hacks.