Handwriting movement data could comply with many excellent formats proposed or under development:

MATLAB® MAT-File Format September 2011 Rereleased for Version 7.13 (Release 2011b)

3D Biomechanics Data Standard (www.c3d.org). This web site provides definitive information about the C3D file format for programmers, manufacturers and end-users. The C3D format is a public domain, binary file format that has been used in Biomechanics, Animation and Gait Analysis laboratories to record synchronized 3D and analog data since the mid 1980's. It is supported by all 3D major Motion Capture System manufacturers, as well as other companies in the Biomechanics, Motion Capture and Animation Industries. The BTK-Toolbox is an open-source and cross-platform library (Mac, Linux, Windows) for reading and editing c3d files. For matlab wrapping, you can download a binary or compiled version on : http://code.google.com/p/b-tk/downloads/list A full documentation is available on http://b-tk.googlecode.com/svn/doc/M...0.1/index.html.

Movement and Gesture. Alexander Refsum Jensenius, Nicolas Castagn, Antonio Camurri, Esteban Maestre, Joseph Malloch, Douglas McGilvray (2007). A Summary of Formats for Streaming and Storing Music-Related Movement and Gesture data.
This paper summarises a panel discussion at the 2007 International Computer Music Conference on movement and gesture data formats, presents some of the formats currently in development in the computer music community, and outlines some of the challenges involved in future development.

Eye movements IST-2003-511598 (NoE) COGAIN, Communication by Gaze Interaction, D2.2 Requirements for the Common Format of Eye Movement Data (2005).

MovAlyzeR® uses mostly ascii space-separated values, some ascii comma-separated values (CSV), and database in Faircom c-tree. This architecture was chosen to enable user-applications (External Apps) to read, change, and write source data and intermediate data. The External Apps can be any executable that can be started from a Dos batch procedure or a Matlab Script. MovAlyzeR imports a variety of input data including CSV, Eyelink, Oasis ASCII, NICI-XYF, and image formats: PNG, BMP, GIF, JPG or PCX.