user4527: I am thinking about buying some Teensy micro-controllers, but I want to know if the teensy are compatible with the arduino keyboard library. 

user17096: It looks like the Teensy designer uses the standard Arduino mouse and keyboard library:
https://www.pjrc.com/teensy/td_keyboard.html
On another note, I'm sure Teensy is a fine product, but I prefer other open hardware solutions like Pro Micro which can be had on AliExpress.com for  under $4 ea.

4527: <p>I am thinking about buying some Teensy micro-controllers, but I want to know if the <a href="https://www.adafruit.com/?q=teensy&amp;" rel="nofollow">teensy</a> are compatible with the <a href="https://www.arduino.cc/en/Reference/MouseKeyboard" rel="nofollow">arduino keyboard library.</a> </p>
 17096: <p>It looks like the Teensy designer uses the standard Arduino mouse and keyboard library:</p>

<p><a href="https://www.pjrc.com/teensy/td_keyboard.html" rel="nofollow">https://www.pjrc.com/teensy/td_keyboard.html</a></p>

<p>On another note, I'm sure Teensy is a fine product, but I prefer other open hardware solutions like Pro Micro which can be had on <a href="http://www.aliexpress.com/w/wholesale-arduino-pro-micro.html?spm=2114.01010208.0.334.k7qlR1&amp;site=glo&amp;SearchText=arduino%20pro%20micro&amp;g=y&amp;SortType=price_asc&amp;groupsort=1" rel="nofollow">AliExpress.com for  under $4 ea.</a></p>
