When it comes to numbers of applications iPad has far more than Surface RT, and neither one has the number of business applications that support traditional Windows operating systems. Surface RT is a Windows operating system that can't run traditional Windows apps except for the Office suite specifically crafted for the platform.
Instead, Surface RT has its own class of applications called Windows Store apps, mainly because they can only be bought from the Window Store. They are tailored for touch tablets and must be vetted by Microsoft before they get into the store's inventory.
They can be developed using XAML, with code-behind in C++, C#, or Visual Basic, and Microsoft has a provision for sideloading custom business apps to Surface RT without submitting them first to Microsoft. Even so, that's a lot of work to get apps natively on the devices.
Both iPads and Surfaces support virtual desktops, which goes a long way toward making traditional apps available on them. Hosted virtual desktops (HVD) can be costly, Gartner says in a report called "Bring Your Own Device: New Opportunities, New Challenges". Its research found that "shifting to an HVD model increases the onetime costs per device by more than $600." Plus proper licensing of iPads for business use is complicated, the report says.
Managing Surface RT is possible via Windows cloud-based management Intune and Exchange ActiveSync for messaging. IPad also supports Exchange ActiveSync. Third-party mobile device management platforms can configure and update iPads as well as monitor compliance with corporate policies. They can also wipe or lock lost and stolen machines. OS X server can do all this as well.