Is it possible to write software on the mac that will launch other separate applications, tell them what to do, etc etc? What language would best suite doing this? (Assuming it's Mac specific).
I'm fairly new to Mac programming, though I have a strong background in iOS. I've seen multiple companies in the past write a script that will cross-compile source code, basically you run your app from the Terminal and it floats around your OS, grabbing what it needs to compile and spits out an Xcode, Eclipse and Unity-ready versions of your source code. I'm familiar with iOS, and how it crashes the second you try to use another apps resources. That is what leads me to the original question:
Is it possible to write software on the mac that will launch other separate applications, tell them what to do, etc etc? Specifically tasks like launch Safari, take a screenshot, launch disk utility, launch mail, email screenshot. I know that OS X allows you to play around a bit more than iOS, but the question is how much.
It's still rather up to what each app will let you do, rather than just being able to do anything, but take a look at OS X's scripting/automation abilities. Primarily this is accessed through AppleScript, but there's now a JavaScript frontend as well (new to Yosemite).
If you're looking at building a native application that takes advantage of other applications, the same scripting abilities can also be reached via the Scripting Bridge from Cocoa (Objective-C/Swift).