Paul Taylor wrote:
It was Vaughan Pratt who first introduced the Wikipedia thread, in response to someone who said that he hadn't heard of Heyting algebras. ... I have changed the Subject line because Wikipedia is not the only site of its kind. Anyone thinking of writing for it should perhaps also consider: - citizendium.org - which looks like Wikpedia because it is run by the latter's co-founder and now unperson; citizendium has a strict policy of using real names and qualifications; - planetmath.org - in which authors "own" the pages that they have written until they've demonstrably abandoned them; - mathworld.wolfram.com - beware that this is owned by Wolfram.
This is off-topic only to the extent that it concerns a publication medium that is as open to articles on the animal liberation movement as it is to those on toposes, subobject classifiers (separate from toposes!) and abelian categories. Wikipedia's flexibility has its pros and cons. While it is potentially as corruptible as communism, by its nature it is dominated by the intelligentsia rather than either the bourgeoisie or the proletariat. Common sense being uniformly albeit sparsely distributed among all three classes, there is no apriori reason why domination of this kind should handicap it any more than its competitors. A significant advantage of Wikipedia is that it was there first (among those open encyclopedias that have amounted to anything) and has become the Microsoft of its genre much faster than Microsoft itself. The fact that some academics remain skeptical of its quality is not in practice a serious differentiator from its competitors. Articles vary widely in quality. I'm presently involved in a dispute over replacing an account of Boolean algebra at http://en.wikipedia.org/wiki/Boolean_logic with my version of that story at http://en.wikipedia.org/wiki/Boolean_algebra_%28introduction%29 . The latter did not exactly spring full grown from my brow---I started out with http://en.wikipedia.org/wiki/Boolean_algebras_canonically_defined as a kind of protest against what I perceived as outdated and parochial views of the subject but then realized that this was pretty avant garde compared to what was needed and toned it down to http://en.wikipedia.org/wiki/Boolean_algebra_%28logic%29 . But pretty soon it became clear to me that this too was pitched at too high a level for Wikipedia and I tried again with http://en.wikipedia.org/wiki/Boolean_algebra_%28introduction%29 . I'm sure that can be simplified too, but the author of http://en.wikipedia.org/wiki/Boolean_logic has utterly failed to convince me that his account is the way to go. Meanwhile I've wrestled with other appalling accounts of topics such as residuated lattices (I completely replaced an article that in effect defined them to be Heyting algebras) and relation algebras (replacing an article that faithfully transcribed all the metamathematical Greek letters in Tarski and Givant's "Set Theory without Variables" in favor of notation more appropriate to an account of a variety). Then there's articles on dynamic logic, Zhegalkin polynomials, and Zhegalkin himself. Another timesink is the pseudoscience that well-intentioned but under-calibrated editors have to struggle with, such as the Wolfram prize for a supposedly tiny universal Turing machine, and Burgin's notion of "super-recursive algorithm" as his proposed counterexample to the Church-Turing thesis. In short, much like the real world, which still hasn't converged on Utopia despite trying hard and wishing harder. Wikipedia and the world are difficult but vibrant and growing communities and I hold out great hopes for the future of both. Vaughan