Public Free PAAS and VirtualEnv

http://cloud-computing.findthebest.com/saved_search/Best-PaaS-Cloud-Computing-Providers

http://equallytrue.blogspot.in/2012/05/free-paas-options-for-deving.html


Isolate VirtualEnv http://www.virtualenv.org/en/latest/#what-it-does


https://openshift.redhat.com/app/

https://cloud.google.com/products/?utm_source=google&utm_medium=cpc&utm_campaign=appengine-search-global

Cloudfoundary & Heroku are among the best one in PaaS category. 

• Windows Azure – Microsoft’s SaaS/PaaS offering for .NET, Node.js, Java, and PHP

• Google App Engine – supports Java, Python, and Go

PHP-specific PaaS

• PHPFog – Heroku-like PaaS for PHP
• Orchestra – PHP PaaS recently acquired by rock star Ruby hosting providerEngine Yard :
• PagodaBox – new upstart in PHP PaaS with a lot of great developer features and one of the coolest hosting dashboards I’ve ever seen

Also, i forgot to mention about Cloudways.com. They are also offering PaaS with lots of features embedded in their basic click & go cloud package which is available with "Free Trial" https://www.cloudways.com/en/pac...