i have DVD RW in g5 machine
can you suggest me mac os 10.3 and 10.4 compatible third party writing software.
Probably the best CD/DVD writing software is Toast, sold by
http://www.roxio.com
If your DVD writer isn't an Apple drive, if you have iLife 5 you can now save your DVD projects as Image files, which can then be burnt to DVD using something like Toast.
There's also a free piece of software called Patchburn:
http://www.patchburn.de/
which lets your Mac treat some third party drives as native Apple drives.
I hope this helps, let me know if you need more information.
Marcus