Free and Open Source Licensing
1. Free software - GNU General Public License (GPL)
For the Helix DNA Client and Helix Player, the GPL is a widely used and popular open source license. It contains a "copyleft" or "force-sharing'" provision, that requires developers to open source their resultant Helix DNA-based product's source code.
2. OSI-certified open source - RealNetworks Public Source License (RPSL)
This license is an approved Open Source Initiative open source license. It contains some "copyleft" provisions along the lines of the GPL, but allows contributed changes to be put back into the pool for the entire community, and allows for wider compatibility with other OSI-certified licenses. Hence, the RPSL gives you the right to develop and distribute Helix DNA, but modifications to the Helix DNA itself need to be supplied back to the community under the RPSL. Also, applications built using the Helix DNA must be released wholly as open source.
You can view the terms of the RPSL to see whether it fits your needs. By downloading the Helix DNA source code you agree to abide by either the open source GPL or RPSL or commercial license.
3. Helix™ Compatible
Source Licenses
Compatible Source Licenses for the RealNetworks Public Source License
can be found here