Lernstift -- German for 'Learning Pen' -- is a twist on the classic concept of a smart pen which uses some clever technology to bring the best of the digital realm to the very analogue art of handwriting.Developed, originally, as a means of improving one of the co-inventor's son's homework, the system is based around an ultra-compact computer -- a variant of the Gumstix Overo computer-on-module which runs a customised Linux distribution.With integrated motion sensor, the pen is capable of recognising handwriting -- and subjecting it to some very clever analysis.Primarily, the Lernstift is designed to be used in orthography mode.In this mode, the system translates handwritten notes into text and subjects it to spelling checks.If a word has been written incorrectly, the pen vibrates -- alerting the use in much the same way as the traditional red squiggly line would in a word processing application.A second mode, calligraphy mode, is designed to improve penmanship in young children by recognising when the shape of a letter may be difficult to read.In addition to these two educationally-focused modes, the pen can also perform the same tricks as a traditional smart pen.Handwritten notes can be saved as images or turned into editable text, and images can be captured without having to scan the paper.The team behind the project promises to release its application programming interface (API) under an open licence, to allow third parties to connect to the pen -- using an embedded Wi-Fi radio -- from desktops, laptops or mobile devices and create applications that can make use of its capabilities.