That's an interesting question. There are so many platforms out there, so I think you don't need to know one, rather you need to have some knowledge about whats happenning, so for example to develop eLearning the Articulate package is very well known but there are a lot of cloud tools and tools that are based on html5. So it's less about knowing one tool if you want to become an instructional designer, and perhaps more about having a pedalogical background and then learn about the tools.

That's an interesting question. There are so many platforms out there, so I think you don't need to know one, rather you need to have some knowledge about whats happenning, so for example to develop eLearning the Articulate package is very well known but there are a lot of cloud tools and tools that are based on html5. So it's less about knowing one tool if you want to become an instructional designer, and perhaps more about having a pedalogical background and then learn about the tools.