Cloud9 is the default development environment used in this class for the following reasons:
- graders will be grading your assignment on Cloud9 (which is Ubuntu/linux), so please make sure your submissions compile and run as expected on Cloud9 before submitting as compilers behave differently on different operating systems
- instructors will not be able to log into your workspace and help troubleshoot and add comments to your code if you do not use Cloud9 (but if you do not need this type of help from instructors, then it's not a big deal)
- Cloud9 probably has redundant hardware so your files will be safer (it is more likely that your hard drive will crash before Cloud9's farm of hard drives crash)