Fritzing : Fritzing is an open-source initiative to support designers and artists to take the step from physical prototyping to actual product.
RACHEL is a portable plug-and-play server which stores educational websites and makes that content available over any local (offline) wireless connection. RACHEL makes deploying a library of digital content as easy as pushing a button.
Then simply turn it on. While RACHEL is on, take your device and connect to "RACHEL" as you would any wifi network. Then open a web browser and type the web address (a number listed on the front sticker of your RACHEL).
Once you're connected to RACHEL, you can instantly access offline versions of the world's best free educational websites including Wikipedia, Khan Academy, and over 100 more.