He’s running Android Donut on a TI nSpire CX graphing calculator. Unlike just about every other TI calculator, homebrew developers are locked out of the nSpire CX and CX CAS.

Seven models of the TI-Nspire CAS are on the College Board’s list. The ACT, which competes with the College Board for test-takers, prohibits calculators with CAS functionality.

The Texas Instruments TI-Nspire CX II CAS is one of the most advanced graphing calculators you'll find, so if your student doesn't have a need for advanced functions and geometric animations, go ...

With the TI-Nspire CX and TI-Nspire CAS handhelds' new 3D graphing capabilities, students can explore concepts from multiple points of view to develop deeper conceptual understanding.

The TI-Nspire and TI-Nspire apps for iPad run $29.99 each and support iPad second generation or newer and iPad mini. A one-year license for the TI-Nspire/TI-Nspire CAS Teacher Software is included ...

More here (complete with annoying music). There is also a computer software-only version of the NSpire, so you can use the CAS without owning the calculator. That sounds more likely to be useful.

Doom has been ported to a calculator. Both TI-Nspire and TI-Nspire CAS models support the video game, thanks to the work of the clever guys at the Omnimaga forums.

It’s great to see Linux running on a device in a way that was never intended. [tangrs] has successfully run a Linux kernel on the ARM based Nspire CAS CX graphing calculator. He’s devel… ...

The TI-Nspire and TI-Nspire apps for iPad run $29.99 each and support iPad second generation or newer and iPad mini. A one-year license for the TI-Nspire/TI-Nspire CAS Teacher Software is included ...