1. Introduction

The SignWriting system was developed by Valerie Sutton, of the Center for Sutton Movement Writing (Ca., USA), as a writing system for deaf sign languages. As is widely know, deaf people have not yet established a standard way for putting their native sign languages in written form, and the SignWriting system is one of the systems that are currently being proposed for such end. Alternative systems for writing sign languages exist, and they have already been compared (see papers in the SignWriting linguistic forum).

As deaf people don't get tired to explain, the implication of deafness is a linguistic and cultural difference between deaf and hearing persons: deafness implies a particular way of people developing their communication functions during their development in early childhood, and with this language difference comes other differences (cognitive, etc.) that impact both the way deaf children develop and the way they should be educated (see papers in the SignWriting education forum).

Moreover, during adulthood, communication in sign languages implies particular ways of dealing with social interactions (at home, among friends, in the work, etc.) so that deaf people are naturally led to organize deaf communities within the hearing societies in which they are being hosted. Such deaf communities have their own social structures (values, habits, jokes, traditions, history, etc.), developed in such a degree that they constitute in fact a culture of their own, the so-called Deaf Culture [1, 2].

This paper is organized as follows. Section 2 gives a brief introduction to the SignWriting system, giving examples of its symbol set and of the way symbols are put together to represent signs. It also explains why we have chosen it as the preferred means for writing deaf sign languages.

Section 3 presents SWML (SignWriting Markup Language), an XML-based format that we are defining for the interoperable storage and processing of sign language documents. Section 4 gives examples of SignWriting symbols represented as SVG symbols, showing how the full SignWriting Symbol Sequence will be represented in a standard way in the single SSS.svg file, which is can be used as a symbol file (analogous to a font file) when rendering stand-alone SWML documents, as well as when inserting SWML islands in HTML documents.

Section 5 tackles the problem of searching sign language texts. We present a simple means that we have devised for searching such texts. Given the graphical nature of SignWriting, a graphical pattern matching method is needed, which can deal in controlled ways with the personal variations people can imprint in the way they write signs. The solution we present introduces a concept of graphical coherence between symbols, allowing for a sort of fuzzy graphical pattern matching procedure for signs.

Finally, Section 6 presents the prospects for an SWML based web application that we started to develop, namely, a sign language webmail system (SW-Webmail). The Conclusion, indicating short-term and long-term future works, as well as including a call for cooperation, is in Section 7.