KDevelop is a decent editor for Rails projects. It gives a nice class browser view of your Rails project.
To resolve the error:
E: Package kdevelop has no installation candidate
before install, Go to :
1. Applications -> System Tools -> KPackage Edit
2. Settings -> Edit Software Sources -> Updates tab
3. Check "Unsupported Updates"
4. sudo apt-get update
5. Run : sudo apt-get install kdevelop
Alternate way:
1. sudo add-apt-repository ppa:kubuntu-ppa/backports
2. sudo apt-get update
3. sudo apt-get install kdevelop
To run KDevelop, just type kdevelop on the terminal
