You can get the latest revision of Papervision3D from the SVN repository:
You must have a Subversion client installed before you can use it. Although you can theoretically download files without Subversion, this would mean tediously downloading each individual file manually.
On Windows, we recommend TortoiseSVN.
Once installed, create a folder where you want to put the source files, open the folder, right click (anywhere inside the folder) and select svn checkout. In the dialogue that pops up fill in the SVN URL.
On OS X, we recommend SVNX.
This gives you a pleasant GUI where you can set up Repositories, connect to them, and simply drag