Georgeism (often also referred to as 'Geoism'), named after its founder Henry George, holds that the cause of most modern society's problems are due to the monopolisation of land, which allows a privileged few to achieve massive unearned wealth at the expense of the many who do not own land, or if they do, who only their own dwelling.
This critical issue has, in practice, been overlooked by just about every other purportedly progressive political philosophy.
The solution to the social inequity and severe economic distortions to our economy are held to be form of progressive tax on the unimproved value of land. So, as an example, a property speculator, whose land value were to appreciate due to, as an example the construction of a nearby railway line, would not benefit unduly from the expense incurred by society in building that railway line.
One limitation that Georgeism appears to share with many other progressive political philosphies, is an inadequate acknowledgement of the physical constraints of our planet, which may make it very diffcult for a utopian society to be established with 6.5 billion human inhabitants.
For further infomration, visit the web site of "Prosper Australia", the main Georgeist group in Australia www.prosper.org.au