AngularJS Learning Playground ( with Twitter bootstrap, Google maps API, TDD using Karma runner )
Bot Command Center for testing the GitterBotX
HTML, CSS and JavaScript playground
playground for code about quaternions
Interactive Playground / Literate Programming for Scala —
HTML, CSS and JavaScript playground
3D playground
Welcome for discussing GreenGrass API Playground — https://github.com/Yxine/GreenGrassAPI
Data Science stuff
Playground for Mimosa 2.0, Marionette Apps with node-orm2 + Semantic UI support (coming)
Dielectric is a playground for coming up with a more functional way of interacting with Spark.
A playground repo for APIs