As a practical example, I'd like to be able to fix http://tools.wikimedia.de/~interiot/cgi-bin/queries/grep but it seems that I will have to make my own tool for the purpose.
Or you could copy-and-adapt. Letting everyone edit everyones tools is - from a security perspective - just plain stupid. The owner of a tool is responsible for it, not some 'list of persons'. I'd rather suggest pushing people to use SVN than to put source code on a wiki.
--valhallasw