Guardfather's top free software and services picks.
Ubuntu has a great feature called the Ubuntu Software Center. Unless otherwise stated, any software listed here should be available in the current version of Ubuntu's Software Center, with a full description. I will still include links to the web pages for each program for convenience.
Eclipse is my first choice for a programming IDE. I have dabbled slightly in a few other IDEs, but Eclipse is the only one I felt comfortable with. It took a little while for me to adjust, being used to more basic text editors geared toward markup languages, but Eclipse has proven itself very convenient for programming.
Bluefish is a text editor much like Notepad++. Syntax highlighting for most major languages, auto-completion, macros, search and replace, and many more features are supported. I used Bluefish for writing Java apps until I got used to Eclipse. I still use Bluefish for HTML and CSS.