Personal experience of Working on Cloud9 IDE
A month earlier i was newbie for online IDE like Cloud9. I need to complete angular-phonecat app via cloud9, as the name defines angular-phonecat is a Open source tutorial offered by angularjs.org. At the start i don't make seperate id for Cloud9 as i was able to sign in with github account.
Creating Workspace is quite easy in Cloud, all you need to do is just click on create a new workspace and give it a name and your workspace will be ready to work in short while.
Problems i have faced: The location where webserver is started http://localhost:8000/app/index.html was not accessible either from c9 interface or in browser.
When i run protractor it was unable to capture browser in 6000ms and the process is killed.
For the above reasons i was unable to write unit test for Angular-phonecat app by own on cloud9
Merits of Cloud9 Online IDE
Workspace size: On cloud9, first of all we need to create our workspace. for free workspace(Linux Machine) you got a memory size of 512 MB and Disk Size of 1GB with certain CPU capability.