Hi everybody.
I have a proyect about a VoIP telephone exchange, i would like to use AsterikNow but a teacher told me that Asterisk is no longer free because is allied with Digium or something like this.
I only need to now if AsteriskNow is free.
Please send me the answer to noel[.]garcia[@]itca[.]edu [.] sv
Sorry for my bad english. My native languaje Spanish 
Digium is the primary sponsor of the Asterisk project and Asterisk is open source. AsteriskNow is basically a turnkey solution, Linux distro with Asterisk and a GUI.
A simple search gives this:
[code]What is Asterisk?
Asterisk, the world’s most popular open source communications project, is free, open source software that converts an ordinary computer into a feature-rich voice communications server. Asterisk makes it simple to create and deploy a wide range of telephony applications and services, including IP PBXs, VoIP gateways, call center ACDs and IVR systems.
Asterisk is released as open source under the GNU General Public License (GPL), and it is available for download free of charge. Asterisk® is the leading open source telephony project and the Asterisk community has been ranked as a key factor in the growth of VoIP.[/code]
this can be found here asterisk.org/asterisk
From a learning point of view, you should configure Asterisk directly. Asterisk GUIs should really be seen as productivity aids for people who already know what the underlying system can do and have basic configuration debugging skills.
If you look at these forums you will see that very few questions get answered in the AsteriskNow parts, basically because you need to go down the underlying system to solve any non-trivial problems.