Plugin Development - Customization / Custom Steps

I understand that the way it used to customize like creating own steps etc was different in 4.x version. And it is revamped / improved in 5.x version, at least for Pro edition saying Plugin Development. Also happened to find a Webinar on that.

 

So, the question is that if some wants to write a plugin in 5.1.2 of Open source edition, is it the same was as shown in the Webinar? If no, is there any resource that one can take a look to start with?