SCADA encompasses a large number of providers and technologies. There is no one language that SCADA uses. For the most part, SCADA packages use a proprietary syntax and API that is wholly internal to the application. They then allow scripting, often through VBScript. Many support ActiveX controls. Sometimes you can directly call native code through a dll. Virtually all SCADA packages are now Windows based. (Especially since Foxboro / Invensys abandoned Sun.) There are exceptions, of course. Ignition (by Inductive automation) is Java-based and is therefore platform independent, and uses Python as its scripting language. (I am unaware of any other SCADA package that uses Python.)
There are a handful of SCADA packages that allow free trials. This includes the afore-mentioned Ignition, RedLion.net (borderline between HMI and SCADA), and Iconics. You could download one of these and check it out.
