Cloud 9 is the best IDE for developers, but it requires credit card.
Here we discuss how to create c9 account without credit card.
At first Create account from www.edx.org
After that go to cs50 IDE
Autherize your edx account to login.
Then go to cloud 9 account. Here is the trick.
Use Your Email to login, user exists but password wrong.
Use Forget Password to reset the password
Enjoy Cloud 9 with out Credit card.