FPlayer is open source.
From the site:
FPlayer :: Open Source AS3 FLV Player
Project
FPlayer is an object oriented, open
source FLV Player Project, coded using
Adobe Actionscript 3.
You can use FPlayer to show videos on
your web projects, develop it and
change its skin easily.
With XML playlist option you can
arrange it for showing multiple
videos.
FPlayer doesn’t use any components
unlike the other FLV players and it’s
only 8kb.
FPlayer basicly includes a volume
control button, a video scrubber, and
full screen option.
Info on the upcoming version 3 is here: http://code.google.com/p/fplayer/