Is there an open source in Linux that support DVD+RW/-RW read and
write. I only find UDF2.0 file system for read only, but cannot find
write support in the file system. Does Linux support UDF write using
the file system. I already know DVD+RW tools at
http://fy.chalmers.se/~appro/linux/DVD+RW/
But that is not what I want.....

Dear cmacma-ga,

You might want to have a look at

    http://www.storagelabs.com

which is a small Dutch company who has a UDF file system.
I am not aware of their licence conditions, though.

UDF write support should work... You need to add CD packet write support
(patches available from http://w1.894.telia.com/~u89404340/patches/packet/).
Depending on your kernel version, you may also need kernel UDF patches
(http://sourceforge.net/projects/linux-udf/), as well as the udftools available
from either of the two sites.

Then enable packet writing (CDROM_PKTCDVD) and UDF writing, and you should be
set to go.  See the instructions in linux/Documentation/cdrom/packet-writing.txt
(included in the first patch above) on how to prepare your CD-RW or DVD+/-RW
for mounting. The preparation steps are a bit odd, but once the disk is
set up, you just mount it and read/write it like any other filesystem.