Unix and Unix-like Systems
The FreeS/WAN and forks such as Openswan and strongSwan offer VPNs which can also operate in OE mode using IPsec based technology. Obfuscated TCP is another method of implementing OE.
Read more about this topic: Opportunistic Encryption
Famous quotes containing the word systems:
“Not out of those, on whom systems of education have exhausted their culture, comes the helpful giant to destroy the old or to build the new, but out of unhandselled savage nature, out of terrible Druids and Berserkirs, come at last Alfred and Shakespeare.”
—Ralph Waldo Emerson (1803–1882)