Ruby on Rails
Ruby on Rails, or simply "Rails" is an MVC framework written in the Ruby programming language. It's known for its speed as a full-stack web development platform, and it also includes many common libraries that are used across almost all web applications (like authentication modules, error handling tools, file upload capabilities, etc).
Rails is just a framework, though, which means you'll need to choose a database to use with it. There are many popular database management systems that can be used in conjunction with Rails (MySQL, PostgreSQL, MongoDB, Cassandra/DataStax...), but the most common choice is MySQL. Keep in mind that MySQL's popularity means most web hosts offer it, so you won't usually need to install/configure your own copy of MySQL.
Most tutorials which teach beginners how to build websites with Rails start out with displaying a list of blog posts and then editing those posts (you'd do this by clicking the "New Post" or "Edit Post" links), but that's not what we're going to do here.
Best Ruby sites
reddit (website) was created in June 2005 by Steve Huffman and Alexis Ohanian with ruby sites when they were both 22-years old. Back then, reddit's main purpose was to be a place where people could post interesting links about websites, images, videos, news stories, and other things from around the Internet. Nowadays, reddit is known more for the wide variety of diverse communities (known as subreddits) where people can share their opinions on pretty much anything. The site receives over 2 billion page views per month, and about 5 million unique visitors…
GitHub is a web-based hosting service for software development projects that use the Git revision control system. It's extremely popular as a place to share code built with ruby sites, and it's home to over 10 million software developers working with nearly 36 million projects (and about 3 billion total files).
GitHub was created back in 2007 by Tom Preston-Werner, Chris Wanstrath, and P. J. Hyett after they realized that developers were constantly sending each other emails about helping each other with Git projects over Yahoo Messenger or similar services.
Quora, a question-and-answer site founded in 2009 by Adam D'Angelo and Charlie Cheever
Quora is a question-and-answer site where people can ask questions about pretty much anything, and then other people can answer those questions.
Quora was founded in 2009 by Adam D'Angelo (the former CTO of Facebook) and Charlie Cheever (a tech lead at Quora until 2014). The site was created to be a place where you could ask your friends for help understanding something, but then the people who answered your question could easily be found by search engines as well.
Shopify, a payment-processing platform for online stores founded in 2004
Shopify is an ecommerce company that provides hosting and technical support for online stores built with its software (for example, Uber uses Shopify to manage their online store).
The company was founded in 2004 by Tobias Lütke, Daniel Weinand, and Scott Lake (the founders later brought on other employees to help them grow the business). The site's goal is to give people a simple way to sell products they create or curate online without having to build their own ecommerce site, and it also makes money by taking a small percentage of every sale that's made using their platform.
Zendesk, a customer support platform founded in 2007
Zendesk is a software company with tools to help businesses manage and provide support to customers (phone, email, social media, etc.).
Zendesk was created in 2007 by Mikkel Svane, Alexander Aghassipour, and Morten Primdahl. The idea for Zendesk came from Mikkel's experience trying to manage customer service on his prior software company (an online ticketing system for event organizers).
Pandora Radio, an internet radio service founded in 2000
Pandora is a music streaming service that lets users create personalized stations or playlists based on their favorite artists and songs.
Pandora was created in 2000 by Will Glaser, Jon Kraft, and Tom Conrad (three former employees of the music software company Spinner). Pandora was created in part to help people discover new music, and also as a way of competing with other radio services like Rdio and Spotify.