Hi there, Well, here I am again, bouncing off the churn that is Swift. I thought I'd test whether Swift Playgrounds might actually be a decent prototyping tool, went to a Demo titled Build your first Playgrounds app and it is already obsoleted by changes to Swift. So, how do we reconcile ourselves to a coding language that changes to rapidly that code becomes obsolete in a matter of months? Is there going to be a list of API's et al that can be considered to be stable? So, the presenter. uses: "    let teas: OrderedSet = ["Byte's Oolong", "Golden Tippy Assam", "English Breakfast", "Matt P's Tea Party", "Darjeeling", "Genmaicha", "Jasmine Green", "Vanilla Rooibos"]" and fixes the error by using: "import Collections" That import no longer exists, and the OrderedSet error she fixed using that Module flags the same error. Can we help me to understand why this simple process of making a list is so challenging for me, the newbie. Are there plans to stabilize Swift, or support Legacy code in the future? That's bearing in mind that I've written some pretty impressive tools in Tk/tcl, C, Pascal. Thanks. Harley