Nimbula, led by former Amazon EC2 developer Chris Pinkham, is now offering a free beta download of its software. The software creates Amazon-like clouds behind the enterprise firewall. Software automatically configures a private data centers hardware into a compute cloud that acts much like Amazon’s EC2. Software also controls access to public cloud resources, letting customers pursue a hybrid approach to cloud computing. The company says general availability will occur in the first half of 2011; it’s running behind schedule.”]