Image: Screenshot/Webmonkey.

Modern.IE consists of three main tools — a site scanner that will look at your code and detect potential problems for older versions of IE, a cross-browser testing tool (part of a partnership with BrowserStack) and a set of guidelines for building sites with web standards.

The most useful of the bunch is the first, the site scanner. Plug your URL into the scanner and it will come back with a list of possible compatibility problems, some unique to older versions of IE, some more general, like outdated JavaScript libraries. Like other tools of this sort — think Yahoo’s YSlow, but here the emphasis is cross-browser compatibility rather than speed — Modern.IE then offers suggestions for fixing the problem.

Or at least usually it does. In some cases it will apparently tell you to get in touch with Microsoft engineers instead for what Microsoft’s Ryan Gavin calls “security and privacy reasons.” It’s also worth noting that Modern.IE still suggests running your site through Compat Inspector, and of course, while Modern.IE is handy for catching larger issues it’s no substitute for actual cross-browser testing.

Microsoft has also included two suggestions that may irritate some developers — adding two snippets of Microsoft-specific code. The first is pretty innocuous, it’s just a bit of code to set an image so users can add your site to the new Windows 8 home screen with a “tile.” Yes, it’s Microsoft-specific code, but the Win 8 home screen images are no different than the Apple-specific apple-touch-icon code that’s probably on your site right now. The second suggestion is to add a bit of CSS to support Microsoft’s proposed MSPointers API. The MSPointers API actually looks quite useful, but suggesting developers use it now smacks of hypocrisy given that elsewhere on the site Microsoft suggests that developers stick to “stable standards.” The MSPointers API isn’t a standard at all, let alone stable.

The second major part of Modern.IE is Microsoft’s partnership with BrowserStack, a service that offers live, web-based browser testing through virtual machines. As part of the partnership you can use BrowserStack free for three months. After that BrowserStack’s regular pricing starts at $20/month for individuals.

Microsoft has also put together “back level versions of Windows and Internet Explorer” as virtual machine images so you can do your more thorough testing locally if you prefer. That means Windows XP, Windows Vista and Windows 7 operating systems with their companion browser versions IE6, 7, 8 and 9. At the moment there are only images available for Windows Server, but a Microsoft representative tells Webmonkey that VMs for Mac And Linux will be available later today.

The last part of Modern.IE is the “code with standards” section which offers an article on “20 tips for building modern sites while supporting old versions of IE.” Most of the advice is sound, though it does advocate for a conservative approach to web standards that’s not necessarily in keeping with the pace of the web.

That last aspect may put some developers off, though it’s worth noting that the Modern.IE site does not adhere to its own conservative approach. Instead the site does exactly what most savvy developers are already doing — using HTML5 and CSS 3, but including Modernizer to help make the site work in older versions of IE.

While the site is obviously geared specifically to toward developers that need to get their sites working in older versions of IE, most of the advice — particularly the emphasis on progressive enhancement — is sound advice for anyone building websites today.