At Pathomation, we're big on integration with other software, and we think you should never never ever re-invent the wheel.
PMA.start offers several plugins already, but there are an infinite number of other environments that we don't have a plugin for (yet).
In many cases there's a way around through more general programming capabilities|. We have SDKs as well as a dedicated developer portal.
In a worst case scenario, you can use PMA.start to convert your virtual slides to a universal file format, like (pyramidal) TIFF or HDF5.