If you want to install the Ruby programming language and the Ruby on Rails framework (5 and 6) at this time, take a look at the sections noted below for step by step walk-through of the installation process (along with all the dependencies and familiarization) based on your machine:

1) MacOS local installation - Section 13

2) AWS Cloud9 (cloud-based IDE) - Section 14

3) Windows installation - Section 15

You can choose either of the 3 options above and if you find the local installations (Mac or Windows) a bit difficult or run into issues which you are unable to resolve, then give the AWS Cloud9 web-based IDE a try since it's the easiest to get started with.

These sections will also cover environment specific terminal/command-line/PowerShell familiarization and usage which will come in handy before working with Rails (or programming in general).

[IMPORTANT] You can choose to skip this installation process at this time and do it in Section 3 when we get started using Rails since the next section coming up (Section 2) covering the Ruby programming language will be done using repl; which is an online development environment we can use to write Ruby code without any local installation requirement of anything.

Older announcements:
As of now, different parts of this course are recorded using different development environments or online IDEs. This is due to when the initial recordings were done, or when updates were made to videos, or when an entire section was upgraded. That will always be the case since I'll try to keep the course updated. So don't worry if you see a background change, usually I'll have videos showing whatever environment I use. 

Please don't hesitate to use the Q&A or post to the discussions if you have ANY confusion whatsoever about any of this and other students, the TA (Evgeny) or I will be more than happy to help.

Enjoy!