learndoubleentry.org
This area hosts a web site based on DELT, Double Entry Learning Tool, that allows students to make exercises on double entry bookkeeping, and teachers to prepare exercises for students, if they wish so.
DELT is free software (released under GNU Affero GPL), and it easily installable by users on their own computers.
The advantage of having a common server is that users can share the "firms" that they create (a firm has its own chart of accounts and journal posts), under a Creative Common License, and other users can fork firms from the "public" ones, instead of creating everything from scratch.
Users are warned that the service is provided AS IS, with no guarantees. Each user can easily download a file in which the data of his / her firm is serialized; this file can be used to import the firm to another instance of the application installed somewhere else, or as a simple personal backup.
All firms (or maybe only "freezed" ones, this is still under discussion) are going to be viewable by everybody. This way, a student will be able to make an exercise and send a link to other people asking for hints. Anyway, the essential parts of an exercise are going to be easily exportable in a human-friendly way, in order to be sent as attachments or printed.
