All downloads can be verified using the Apache OpenMeetings code signing KEYS, changes: CHANGELOG.
All are available for download as source and binary.
Latest Official Release
Apache Openmeetings 3.2.1
Previous Official Releases
Apache Openmeetings releases available here: http://archive.apache.org/dist/openmeetings/
Apache Openmeetings Incubating 2.0 is available here: http://archive.apache.org/dist/incubator/openmeetings/2.0-incubating
Plugins / Non ASF downloads
If you are looking for more plugins for 3th party applications (Moodle, Drupal, Joomla, ...) check out github.com or ask commercial support.
OpenMeetings releases that are not part of the ASF can be downloaded from the old GoogleCode website