Flex PBX is an easy-to-use program based PBX system for small and large business alike. It is your virtual receptionist at a fractional of the cost that operates on your own computer. Flex PBX program offers point-and-click installation and easy configuration. With Flex PBX, your computer answers incoming calls like your receptionist does. It processes and transfers calls to responsible parties. Besides all the traditional PBX features including auto attendant, call transfer, call forwarding, call waiting, music on hold, and customized extensions creations, etc, it is also fully integrated with Voicent IVR Studio and Telephony CRM for customer database access and management and email notifications.

Flex PBX Key Features:
1. No setup fee, no recurring costs. Buy it once, own it for life time.
2. Easy Point-and-click custom PBX system design and configuration
3. Works on any PC or laptop with Windows 2000/2003/XP/Vista
4. No special hardware needed, just your computer
5. Works on physical extension and/or VOIP extensions
6. unlimited extensions
7. Unlimited call waiting queue (enterprise version)
8. Unlimited minutes
9. Display call list in waiting queue
10. Personalized greetings for each caller
11. Follow me calling
12. Dial by name or by extension
13. Dial by touch tone key
14. Auto attendant
15. Music on Hold (call waiting)
16. Custom greetings anywhere
17. Personalized message design
18. Customized greetings by day and night, weekday or weekend
19. Caller information preview
20. Queue optimization
21. Voice mail only extension
22. Password protected extension
23. Answer, hold, transfer, park, and un-park call
24. Caller information display (with Voicent telephony CRM package)
25. Voicemail delivery by phone or by email
26. Fully integrated with Voicent IVR Studio

What's the difference between Flex PBX and IVR Studio?
A PBX system is a special and commonly used IVR application. In general, PBX systems are designed for ease of use, and IVR systems are designed for any call flow control and system integration.
You could use Voicent IVR Studio to design your PBX system, but it will not be as easy as using Flex PBX. If you need to integrate your PBX system with a relational database or email server, then you have to use IVR Studio.

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