Rob Clark of Texas Instruments hacked together KMSCUBE and published the work today. He didn't write the KMSCUBE application out of thinking someone is legitimately after having a spinning cube running from their KMS console directly, but rather it's a good exercise for someone wishing to dive into the KMS/DRM, EGL, GBM, etc.
The heart of this KMSCUBE code is just a little over 600 lines of code for communicating with the DRM/KMS drivers, creating the EGL context, and drawing the multi-colored cube using GLES2 with GBM from Mesa to the console. KMSCUBE is very simple and should be easier for new developers to understand than looking at the code to KMSCON (the KMS-based console from user-space) or Wayland's Weston.
For those looking to dive deeper, there's also Jesse Barnes' guide to hacking with EGL and KMS from last year.
Those wanting to checkout the KMSCUBE test application can find Rob Clark's code on GitHub.