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When I check pages for broken links using Xenu's Link Sleuth it usefully lists information about the web server, OS and PHP version

Apache/2.2.11 (Unix) mod_ssl/2.2.11 OpenSSL/0.9.8j PHP5.2.9

Is there a simple way to extract similar information from the browser when viewing a page e.g. by a Javascript snippet/bookmarklet?

The server information is part of the HTTP response header which is not accessible to Javascript. So a Javascript/bookmarklet solution would not be directly possible (though it could do something like sending the page URL to a site like Arjan's below).

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up vote 2 down vote accepted

The Web Developer toolbar for Firefox has among its many options a way to view page response headers. (Information | View Response Headers)

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Aha! I already have the Web Dev toolbar installed but hadn't noticed that menu item. Thanks. – pelms Nov 18 '09 at 17:15
Always happy to help. – Al E. Nov 18 '09 at 18:28
Good answer, but it won't show the operating system (unless the web server includes that), does it? – Arjan Nov 18 '09 at 18:39
Probably. It might require some inference. returns "Server: Microsoft-IIS/7.0" as one of the values. IIS 7 implies Windows Server 2008, does it not? – Al E. Nov 18 '09 at 19:15
Well, there's more than one flavour of Windows ;-) And for some installations the response headers just return "Apache" (like for or "nginx" (like for (But I guess the question asker doesn't really care about that; using the Developer Toolbar surely is an easy way to get some information. And neither the response headers nor Netcraft can figger out what is using...) – Arjan Nov 18 '09 at 20:48

The information you mention seems the same as Netcraft's "What's that site running" provides, and they actually have a toolbar (which I've never used). Still note that this information is not by definition The Truth; a web server can report anything it likes.

Also, it's just never as complete as the real story.

I didn't know IIS could run on Linux? Ah, Jeff says some parts of SO are Linux, like the load balancer (HAProxy).

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Re: Strange, the header just reports 'Microsoft-IIS/7.0'. I wonder where Netcraft gets the OS from. Is this a virtual machine thing??? – pelms Nov 18 '09 at 17:26
Ah, just seen your other link re. OS detection... – pelms Nov 18 '09 at 17:28

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