Integrated Development Environments for Sage
If you have successfully setup an IDE for Sage, please share the process in Meta-ticket #30500: document configuring IDEs and text editors (or a separate ticket).
Emacs
See Emacs
Geany
Sage 5.2
Eclipse
Sage 4.5.0 - 4.5.2
https://groups.google.com/d/topic/sage-support/HTPssIMKMHw/discussion
Netbeans
PyCharm
If you want to use PyCharm for development, just open SAGE_ROOT as a project.
Also see the answers to these ask.sagemath questions:
https://ask.sagemath.org/question/39742/make-pycharm-recognise-the-sage-python-interpreter/
https://ask.sagemath.org/question/38750/how-i-use-sage-with-pycharm-in-ubuntu/
And this StackOverflow post:
https://stackoverflow.com/questions/22133861/launch-pycharm-from-command-line-terminal