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1000 Planets Inc.
Company news and activities - a for-profit space venture looking at space transportation and colonization opportunities.
http://www.1000planets.com/
Alliance to Rescue Civilization
A private foundation, led by William E. Burrows and Robert Shapiro, that aims to backup civilization in facilities away from Earth, to ensure survival in the event of a planetary catastrophe.
http://www.arc-space.org
Blue Origin
Aerospace R&D company working on spacecraft and launch systems with the ultimate goal of contributing to an enduring human presence in space.
http://www.blueorigin.com/
Cygo's Space Initiative
Organization and forum focused on mining the asteroids.
http://cygo.com
Kennedy II Lunar Exploration Project (K2LX)
Proposal to develop the Moon; funding appears to be at least partially from real estate sales. Limited content on site so far.
http://www.kennedyproject.com
LiftPort - The Space Elevator Company
Company devoted to building a vital and highly profitable infrastructure for off-world industry. The Space Elevator is a key enabling technology for any work done off the planet, whether in near-earth orbit, at geosynchronous distances, or far beyond the moon.
http://www.liftport.com/
Orbital Development
Greg Nemitz's space development company.
http://www.orbdev.com/
The Colony Fund
Public venture capital fund for the space entreprenurial sector
http://www.colonyfund.com/
The Eros Project
Space property rights - attempt at legal recognition for a claim to the asteroid Eros.
http://www.erosproject.com/
The L5 Development Group
A privately funded, for profit, space exploration and development program whose initial business plan is to build space colonies at L5 and manufacture solar power satellites to meet the Earth's energy needs
http://L5Development.com