If you know Ruby and you want to write applications for Mac OS X or the iPhone, you’re in a great place to start! This concise and content-packed 80-minute screencast will teach you what you need to know to start programming in Objective-C.
Rails Long Term Support
Rails LTS provides security patches for old versions of Ruby on Rails (2.3, 3.2, 4.2 and 5.2)
Prevents you from data breaches and liability risks