In a disclosed method that facilitates collaborative file updating, data
is accepted from one of a plurality of users and stored. The data
represents an initial version of the file and designates one or more
recipients of the initial version. Then, for each one of sequentially
updated versions of the file, data representing a difference between the
updated version of the file and an immediately previous version of the
file is accepted from a user. The data also designates one or more
recipients of the updated version. Data representative of the updated
version of the file is transmitted to the designated recipients of the
updated version. The data transmitted to each recipient who is designated
as a recipient of the updated version and who accessed the immediately
previous version consists substantially of the difference between the
updated and previous versions of the file. Other methods and systems are
disclosed.