Vbuzzer is all in one instant messaging software that support VoIP, internet fax, RSS, video conferencing, and support Windows Live Messenger, Yahoo Messenger, AIM, and ICQ. VoIP features include free internet calls, low cost PC to phone, and phone to PC calls.
Vbuzzer costs as low as $2.28/month to get a phone number on Vbuzzer, and $0.015/minute for long distance calls within US and Canada. Internet fax features include sending and receiving fax over Vbuzzer Messenger, for receiving fax Vbuzzer can assign a fax number to its instant messaging software
Currently Vbuzzer offers free faxing to any fax machine within US and Canada. Instant messaging features include text messages, file transfer of any file size (without limit), and group messaging. Users can also look up other users by searching by certain criteria and make friends with each other. RSS features include subscribing RSS feeds from users favorite web sites, or from personal blogs of friends or favirate bloggers.
Vbuzzer video mail system also allows users to cast and email video messages on a simple web page without any software download.
Vbuzzer Conferencing System allows multiple users to hold video conference on a web page without any software download and complex configuration.
The free web conferecencing is limited to 4 parties, beyond 4 party web conferencing is a paid service.
Vbuzzer Messenger can work with most networking environments including some strictest enterprise networks with firewalls, it can be downloaded and used with dial-up internet access, however for making telephony calls, it is recommended that users have high speed internet connection.

The license of this software is Freeware, you can free download and free use this internet phone software.