All source code of MageBridge is available for free through GitHub. There is no restriction in its usage, and the free sources are the exact same as offered to paying customers. Note that the free sources are available here for developers, and are offered without support.
Paid subscription for updates and support
Even while MageBridge is advertized as a commercial extension-suite, it's source code is made available through Git for nothing. MageBridge is commercial open source: A fee is asked to receive support and services for a specific period of time. The subscription includes regular updates through the easy-to-use MageBridge Update Manager, and support on the usage of MageBridge.
Note that MageBridge extensions use two separate licenses - the GNU/GPL for Joomla! and the OSL for Magento. This dual licensing guarantees that each single line of programming code is properly licensed, depending on the platform it is based on. The Joomla! extensions are in full compliance with the GNU/GPL. The Magento extensions are in full compliance with the OSL.
With the following URL you can access the GitHub repository of MageBridge through the Git client of your choice.
Refer to the online tutorials for more information: Installing MageBridge using Git