The section on the Customize menu selection (of the File menu) explains how to configure Thinker for the groupware features.
In private file protocol, only one user can access any file at a time as Thinker opens the file read/write and the Mac OS will allow only one of this type of access at a time. Modifications to files are written directly into the document when the Save operation is selected.
In shared file protocol, Thinker opens documents read only. The first user to attempt to change the document will cause an Thinker to create an Update file with the same name as the document file with a ".upd" appended to the name. The Update file is in the same folder as the base document. All changes to the document are written into the Update file when the user selects Save.
Whenever there is an Update file in existence the Apply Updates menu option is active (only for the user that created the Update file). Selecting Apply Updates will attempt to merge the Updates into the base document. Since the Finder does not respect version numbers of files, Thinker must gain read/write access to the base document in order to merge in the updates. This requires that all other readers of the file close it. Some day this awkward situation will be repaired.
This collaboration requires that all shared documents and mailfiles be in well known and commonly available shared folders. Since the names of files in links are full path names, the names of the common folders must be the same for each collaborator. This precludes the use of Prefixes unless the prefixes are agreed upon by all collaborators.
The combination of Mail and Shared file protocol makes Thinker an excellent Hypertext based collaboration system. Such a system is described in the document Collaboration included on the distribution disk.
Mail is composed inside of Thinker and any branch of a Thinker document can be sent as a message as long as it begins "To: userid " where userid is one of the known collaborators. Mail sent to a user is temporarily stored in a mailbox file in straight ASCII so pictures are not transmitted. The mailbox file is assumed to be in the folder named in the customize dialog and should be publicly available (at least to all those who expect to send mail to the receiver). If one is not present, it is created with the name "mail.userid" in the designated folder. When a branch is sent as mail, a time stamp is added at the end of the statement at the head of the branch. It is polite to include a "Subject: subject of message" after the "To: userid" portion of the statement that makes up the branch head. See SendBranch in the Other menu.
When mail is read it is "imported" into a file in the "Mailfile" folder. This folder can be private to the receiving user. Thinker will create this file if it is not present under the name "mailfile.userid". All new messages are imported under the branch with a label of "new" as in "(new)New messages". Thinker will create this branch if necessary. Set CheckMail and GetMail in the Other menu.