Access to download documentation and binaries for NetDocuments EM (Explorer) is by invitation and limited. The files are downloaded via an SFTP site. This is the same as an FTP site, except it is a secure connection and you can't use a browser to access the files. The site is: ftpfiles.netdocuments.com.
Normally, you will have a username and password that was supplied to you by someone at NetDocuments. If not, talk to your sales person or professional services representative. If you are being implemented by a third-party provider, they will be able to get it for you.
When you login, you will see a downloads directory. Inside the R4.x directory there are the directories All, GA, LA, and QA. The only two you care about are the All and GA directories. The All directory gives you access to all of the releases of NetDocuments EM 4.x (Explorer). The GA directory is the Generally Available release. This directory exists because some releases are full releases and others are patches. A patch only contains those files that have changed. It will not contain the entire distribution. The GA directory collects the most recent version of everything from the patches and releases.
Inside each full release there are several sub-directories. The Documentation contains the full documentation for the release. The Database directory contains three sub-directories. The Install directory is the script to be used for a fresh install. The Upgrade directories contains a set of SQL scripts for performing upgrades. There should also be a PDF file named Explorer Release Notes.pdf. It will document the changes and change log for the releases.
The highest release number is the one you should install, or upgrade to. The release notes contains the instructions for upgrading. Any files in this directory have passed Quality Assurance and are ready for production deployment.