A tiny new open source drone kit made by Bitcraze is buzzing its way to market this spring, targeted at hackers and modders who want to explore droning indoors as well as out.

Marcus Eliasson, Arnaud Taffanel, and Tobias Antonsson are the engineers behind the Swedish startup now accepting pre-orders for a palm-sized quadcopter called the Crazyflie Nano. (Not to be confused with the Norwegian-made nano-copter used by British troops in Afghanistan.)

The trio used only open source material for the project, from mechanics to hardware and code. Not only was it a nod to the open source mantra, it saved them a ton of time; all three have day jobs and have spent the last three years working evenings on the Crazyflie Nano.

"We used what is common knowledge from other open source projects, so we kind of used the same building blocks that have been tested by us and by other open source projects," says Eliasson.

Though it looks like barely more than four propellers, a battery, and a control board, the team packed multiple sensors and an antenna onto the tiny frame, in an effort to give developers and hackers more to play with.

"At least we hope that people will use it for that," says Antonsson. "It’s extremely fun to play with as well, just fly around. Our hope is that they will develop on it." They have already gotten suggestions for modifications, and hacked the copter to carry a video camera, LEDs, and even an inductive charger.

The $149 device is controlled by a PC through a 2.4 GHz radio, and an on-board gyroscope and accelerometer keep it steady. (A more advanced, $173 version, with a magnetometer and altimeter will also be available.) The Crazyflie Nano is available on Seeed, an "open hardware facilitator" that also takes pre-orders, somewhat like Kickstarter but with less publicity and no goals to reach.

In fact, the team considered crowdfunding the Crazyflie. "We wanted to keep it fun," says Taffanel. "We didn’t want to say that we were forced to deliver something quickly."

At less than four inches across and 19 grams, the device is small enough to fly under tables and chairs, and through enclosed spaces.

"It won't kill you if you do something wrong with it," says Antonsson. "That's a big benefit if you've been playing with the bigger ones. They can be pretty harmful."