Crux LX, in current form, is fully built using open source software. This includes Debian® operating system and a large set of software that accompanies the distribution and more. Two of the key FOSS components that support the Unified Communications functionality are Asterisk® and FreePBX®. These are being used under the realms of GPL, AGPL and LGPL licenses.
At Crux Labs, we have glued it all together along with our own set of modifications that have made Crux an easy to use and manageable device. Crux is Crux Labs' attempt to make open source work for non-techies in a way that is simplified, easy to manage and cost effective as compared to other commercial products available in the market. This endeavor could not be possible without the large community of open source contributors world-wide that has offered us this opportunity to make open-source consumable for the society.
Crux VX on the other hand bears the same software stack as Crux LX, but in addition to it, it has other proprietary licensed software as well. However, Crux VX ships presently with perpetual licenses, hence, do not attract any recurring expense, just like Crux LX.
Trademarks and Copyrights - Debian®, Asterisk®, FreePBX® are respective registered trademarks of Public Interest, Inc., Digium Inc., and Sangoma Technologies.