Nessus is vulnerability scanner that has web-based interface. You can use it to improve your backtrack funcionalities.
1. Install from apt-get
# apt-get install nessus
2. Follow the instruction displayed (add user). this user will be the administrator user, you can add other type of user later
3. Register to nessus.org to get your activation code. if you have received it, run this command
# /opt/nessus/bin/nessus-fetch –register
4. if this procces doesnt run well, it may be caused by wrong proxy configuration. setting proxy configuration on nessus-fetch.rc will solve it
5. Upgrade your nessus
# apt-get upgrade nessus
6. Run nessus daemon
# /etc/init.d/nessusd start
7. Open your browser and enter https://localhost:8834/
you may login to nessus now.