This hypertext holds a heterogeneous collection of topics - half-and-half between DRW's material created in the 90s and new material created in 2010. Typically, a page comprises an interactive application together with its underlying code. A visitor is welcome to be interested in both aspects of the page.

Occasionally a page will be purely expository.

My students have always had their copies of my hypertexts. To acquire a copy of this hypertext on Topics ask me ( to upload a .zip copy to

The material is freely available to student and teachers. Topics envisaged include:

Some topics might be categorised as: WhWhWh (via the WWW), that is, "What, Whence, Where" meaning "What is it, whence did it come, and where is it deployed now?". [On saying "WhWhWh" I do wonder whether I should say, instead, "hWhWhW".]

The pages will include acknowledgement of people/institutions sharing their work with others, such as:-