Apparently the Cactus Eclipse Plugin is not in development and is
unavailable. Unfortunately, I could not tell that from browsing the
Cactus website. Removing the a link to download the now unavailable
plugin, causing people to search the page and the website in vain, is
not sufficient .
But it *is* available. At least, I managed to find it in a couple of
minutes. The source code is here:
http://svn.apache.org/repos/asf/jakarta/cactus/trunk/integration/eclipse/
and there are binaries available in the Maven central repo.
I don't doubt that it is not actively developed, though,