I have touched on Application Compatibility as part of my multi-post blog series regarding Migrating Applications, for more see HERE Today, it was pointed out to me that my blogs about MED-V were out-dated because it makes it sound like a viable option still, well, it's not. My MED-V blogs can be found HERE .MED-V is about as useful to you now, as XP is. You see, MED-V provides a method to run your old XP apps which are not compatible with your new OS on your new OS! But!! it does this by running the applications on an XP Virtual Machine while presenting the applications to your users on their new OS, your users would likely be completely oblivious that the app is running on XP in the background. It was a pretty nifty solution in my opinion but this was always intended as a bandage and a short term solution to a long term problem. It was to enable early adopters of Windows 7 a means to speed up their migration and provide them more time to address the incompatible elephant in the room :-) Microsoft actually discontinued MED-V in April of 2013. And they were absolutely right to.
So what's the alternatives? Running Virtual machines of XP and hosting incompatible applications on those and publishing to your users? No, you've got the same problem. XP is going away, you need to forget that.
Server 2003 is pretty similar to XP. Server 2003 is also going to be supported by Microsoft until 2015, so there's hope. Do you use Citrix? Well, what version of Citrix XenApp is in your environment, is it 6.5? If so, Terminal Server 2003 is not supported and in this instance you may need to have an older seperate Citrix farm just to house your incompatible applications but this may actually be your best solution. Unfortunately, options are running out due to both the length of time vendors have been developing towards newer platforms and how close we are to the plug being pulled on XP.
There is also the option of paying for extended XP support from Microsoft, which is going to be very costly. A lot out there are saying it's BS that XP is going out of support and that Microsoft are just profiteering. But that's not really the case. Hardware is changing and with that, the software and operating system capabilities exceed the current XP. It's unrealistic to expect Microsoft to continue to support such an outdated operating system and so too, it's crazy to expect software vendors to develop software against what is in todays world a sub-par OS. In all fairness, Microsoft have delayed the XP End Of Life multiple times now. They were also very active in performing Windows 7 Launchpads to help people get over the hump to get the wheel in motion to make the move. They provided MED-V, Shims and Compatibility modes to help also. Upon releasing a new OS, there's training materials and white papers released to help you learn, there's development best practices. Unfortunately, you can lead a horse to water but you can't make him drink. Developers do not adhere to the new best practices until it's too late and the OS is already ready for distribution. I have always made it my duty to download beta versions of new Operating Systems to see what has changed and how they affect my work. This should be something which is common across the enterprise for anybody in a consulting or architect role, at least!
Of course, there is another option...you keep running XP without Microsofts support and patches. This is kind of a nuclear option. It's anybodys guess if there's security flaws which some opportunists are currently sitting on, just waiting to exploit the moment support runs out. Without security patches and support, you're really up a creek without a paddle. You could beef up your security and hope for the best. Maybe look at something like Bromium, beef up your firewalls etc. But I know this wouldn't provide me with enough peace of mind to sleep well while my users and my data is still on XP. Bromium themselves explicity state that they still encourage people to move to a new OS rather than rely on their software.
Really, you need a new compatible version of your software from the vendor. If it's in-house you need to work with your in-house developers to bring the application up to best practices. Tools like AppDNA, Flexera Application Compatibility Pack and Changebase can help guide them on this. Failing that, running incompatible apps in an older Citrix farm can get you by until 2015 but don't sit on your hands during this time. You need to get these in line, sooner rather than later.