In teaching my ESL (English as a Second Language) online course I use a number of Internet tools for education. They include:

• Web based static sites
  This is the kind of site that simply contains information and assignments. Using this kind of site is designed to be a passive experience.
  
• Web based interactive sites
  This kind of site will actually ask the student to do something on the page (e.g complete and submit exercises, contact someone, post to a forum, etc)
  
• Written email
  This can be used to convey social chat, course information, assignments, assessment and feedback.
  
• Voice email
  Similar to normal email except that you attach your messages as voice files. Very useful for students wanting to practice pronunciation.
  
• Real time meetings (chat)
  Students and teachers meet at a prearranged Net based space and 'talk' about assignments, or engage in general discussion.
  
• Forums/bulletin boards
  Students and teachers post information for discussion and reflection.
  
• Student web pages
  Students create their own pages. When students create their own web pages the level of ownership of the learning involved is very high, particularly in collaborative ventures when two or more students work on pages together.
  
• Audio conferencing (real time real talk)
  One to one real time conversations.

Technological Complexity
These various tools can be graded on a continuum from easy to hard (email being the easiest and student web pages the hardest):

Easy

• Email
• Static website
• Interactive website
• Forums / bulletin boards
• Chat (type talk)
• Real Time Real Talk
• Creating web pages

Hard
Looking at this list it is obvious to see why email and static websites are the most convenient way of conducting online teaching. They are not necessarily the most effective, but they may be the only practical online solutions for students who don't have

• high-end computers
• a high level of technical skills
• a high level of English language

Educational Effectiveness (level of interactivity)
Conversely, if measured in terms of their ability to engage students in interactive processes this same set of tools, with the exception of email, can be ranked in reverse order:

Low level of interaction

• Static website
• Interactive website
• Forums / bulletin boards
• Chat (type talk)
• Real Time
• Real Talk
• Creating web pages

High level of interaction
If you run a course that aims for a high level of interaction it may also require a high degree of technical know-how and you run the risk of losing all but the technically competent and highly motivated.

Generic or Specific Learning Environment/Materials?

In my own teaching I have been forced to mix and match the abovementioned tools to cater for students' differing circumstances and needs.

For example,

• Student A may have very slow Internet access and just wants to trade assignments and assessment via email.
• Student B may be able to use email to send assignments but has reasonable enough web access to get instructions and course material from a static website.
• Student C may love and need practicing grammar drills on so-called interactive websites (which are all over the Internet), has the technical facility to do so, and just needs clarification or explanation when he/she needs via email.
• Student D already has good writing and reading skills and just needs to brush up conversational English. These students typically just need one or two meetings a week in a real time chat room. Email may be used to advertise meeting times, and perhaps send written logs of the sessions.
• Student E may be much the same as D but wants to speak and listen to the language. This can be done through real time audio-conferencing tools, and sending sound files as email attachments.
• In all of these the use of email ('the workhorse of the Internet') is used in common. Email can be used effectively to compensate for the lack of inherently interactive software.
  

Is this time consuming? Yes. And throw in all the interactive input necessary to oil an online course and you start to see where the time goes.

Resources

For a handy table that describes the sorts of activities that each tool can be used for go to the Distance Learning Dynamics website.

A longer article that describes similar tools and activities can be found at DU (Diversity University).

ALN (Asynchronous Learning Networks) is another useful starting point for related material.