A reader writes:
I am an artist, who is not very technical, looking for any existing open source code that would enable a web site to pair two videos on a split screen for simultaneously play. The video artist uploading his/her video would simply note which video he or she wanted to appear opposite his or her own video on the split screen and "viola", the videos would be play side by side.
YouTube Doubler and You3b provide the functionality described above, but the reader informed me that she is looking for an open source software package that can be installed on a given site and presumably customized. If you know of such software, or would be willing to work on something similar, please leave any info in the comments.