Here is a collection of Array and Enumerable examples.
I use a MacBook Pro for work and pleasure on a day-to-day basis. Recently, I was asked to teach web students at a local high school. These students know html/graphics/flash/etc. The advanced students were ready for some server-side programming and database integration. I wanted the students to be able to get up and going quickly (for motivation reasons) and to create useful apps (using a database). I felt Sinatra to be a great fit for this. I created a Sinatra app for my uncle and his business. It was a joy to work with it and I was able to deploy quickly using Heroku . My experience of using Sinatra on my Mac was straightforward. Like most things using Ruby and Mac: it just worked. However, I found out the students at the high school use MS Windows. Fortunately, I have a Windows XP virtual machine running in VMWare so I could prepare that way. I used to teach computer science and web development at Spokane Community College and am aware of teaching Ruby in a Windows lab environm