You can frameserve video from one application to another. For example, you can use VirtualDUBs frameserver to serve to encoders like TMPGEnc or CCE SP.
I love this site! But I went to the "Glossary" because I wanted a refresher on exactly what "frameserving" accomplishes in the process of ripping/converting archival DVD copies. This Glossary entry fails to do that. I'm sure many regular contributors could throw together a better definition. Thx ;-)