Excluding (for now) synchronous tools (such as face-to-face meetings and telephone conferencing), these are the older (but still useful) collaboration tools we can think of -

E-mail - ubiquitous and very flexible, but difficult to build coherence [see also the separate section in this chapter on e-mail].

Discussion groups - simplifies broadcasting e-mails to a group, but volume can get overwhelming and lack of coherence remains a problem

Threaded discussions - supposedly allows for greater coherence than plain discussion lists (by linking different threads of the group conversation), but cumbersome and time consuming to use in practice

File sharing by e-mail  - allows for different people to work on a common document, but version control very difficult, especially for larger groups

File sharing via a network - better version control (depending on the system), but difficult to set up.