My sincere thanks for your speedy comments on my comment re anti-plagiarism. I admit that the way I expressed my view somewhat lacked in "openness" and may have been resented as anti-Moodle, which is of course the last thing I want to express!
"The fact is that large numbers of institutions who use Moodle also want to use plagiarism software..."
Probably right, and I lament that fact. Mine is of course a political (but primarily pedagogic) point of view. I'm afraid that it's not so much that many institutions want plagiarism software than commercial firms who produce that software push the institutions into buying it. And those firms certainly do not share Moodle's "open" philosophy, nor do they have pedagogic values, they are only after the money. That is why I lament the fact that, by providing plugins to such plagiarism software, Moodle indirectly promotes values which run counter to what I perceive to be its philosophy.
"Plagiarism tools [...] can be used as an educational tool to help teach students about plagiarism and how to specify bibliography references ".
Point taken, but... do universities need to spend lots of money on such tools for doing something which is (or should be) part and parcel of their normal teaching? I have recently given courses to university students precisely about plagiarism and correct referencing. This is what I mean by "education".
"It's just another "tool" that teachers/institutions can choose to use if they wish"
I have devoted a number of pages in my PhD thesis to the analysis of such concepts as "tool", "instrument", "machine". The frequent expression "[...] is just a tool / is another tool" is usually followed by "... it's not the tool that matters but what you do with it". Pushed to the extreme, we get such (to me horrifying) statements as "guns don't kill, people who use guns do" to justify the (again to me horrifying) number of weapons circulating in the US. A tool is never neutral. Of course you can kill people with a screwdriver or a pair of scissors. Of course you can own a gun and never use it. It remains that a gun has been built to kill.
I beg to disagree with the view is that "if Moodle will supply a plagiarism plugin, it does not mean that Moodle supports the validity of plagiarism software".
Let's see what Martin D. has to say on the matter. And - again- many thanks for taking part in this interesting discussion.