Engineer turned toy-maker Debbie Sterling has just announced a second addition to her bestselling educational playset, GoldieBlox and the Spinning Machine.

Called GoldieBlox and the Parade Float, this new storybook and building kit introduces girls ages 4 to 9 to the wheel-and-axle concept of engineering, plus Goldie’s new friend, Ruby Rails. 

This summer, girls everywhere shocked the toy industry when they drove the engineering playset to the top of the Amazon Toys & Games bestseller list. GoldieBlox gave girls a way to engineer their own inventions and get acquainted with STEM (Science, Technology, Engineering, and Math) fields early in life. 

It was a fulfillment of Sterling’s hypothesis that just because an engineering toy for girls didn’t exist yet didn’t mean there wasn’t a demand for it. In fact, when Sterling launched her Kickstarter for GoldieBlox in October 2012, it earned double its original funding goal. 

See also: How An Engineering Toy For Girls Went From Kickstarter To Bestseller

Sterling originally conceived of GoldieBlox after being frustrated with the lack of options in what she calls the “pink aisle” at the toy store. While some companies turned engineering toys, like Legos and Lincoln Logs, into girl toys simply offering them in pink, Sterling thought the key to getting girls interested was about more than just a color. Her playsets each come with a story book as well as construction tools in order to give girls a reason to care.

“[GoldieBlox] appeals to girls because they aren’t just interested in ‘what’ they’re building … they want to know ‘why,’” she wrote on Kickstarter. “Goldie’s stories relate to girls’ lives. The machines Goldie builds solve problems and help her friends.”

Just in time for the holidays, Goldie’s latest adventure features professional illustrations (Sterling drew the original pictures herself) and a new character of color. 

Ruby Rails, obviously named for Ruby on Rails, the open source web application framework that runs on the Ruby programming language, is billed as a “princess turned engineer.” Ruby came about after black parents began asking Sterling to design a character for aspiring engineers who aren’t “goldies.”

In a further acknowledgement of the toy’s diverse user base, Sterling has also launched an online “play gallery,” in which real girl inventors demonstrate new ways to use their playsets. It’s a clear affirmation of GoldieBlox’s origin as a crowdfunded project, which couldn’t have existed without the support of hundreds of girls and their parents.