What IDEs can you suggest for developing Ruby on Rails applications on Ubuntu 12.10 or higher?
- Code completion
- Syntax highlighting
- Support for a rails project structure
I'd recomend RubyMine.
It's by far the most intelligent Ruby and Rails IDE on the market. Some of the features:
New user advices:
Look and Feel example:
JBaruch's answer is a pretty good fact sheet for RubyMine. I'd like to write an answer that talks about my own personal experiences with the product, in the few days that I've used it (yay for 30-day free trials), along with some of my screenshots.
First, a disclosure: I'm a paying customer of another JetBrains product, IntelliJ IDEA. There are a number of similarities between IDEA and RubyMine, so getting around RubyMine was easy enough for me.
Second, to address all the features required by the OP, here are some screenshots (these are all from a tiny project I wrote from scratch to test RubyMine features; it currently simply generates and shows a Minesweeper board, in case you're wondering what the code is about):
Code completion and syntax highlighting:
Support for Rails project structure:
Rake (and other Rails tools):
Finally, my personal experiences with the product:
There's a nice and comprehensive set of "inspections" (which are like code linters) to help you write clean code and avoid common bugs:
Here's an example of an inspection in action:
There's a handy Ruby gem manager, which can tell you what gems are available to install, as well as the versions you can pick:
Unfortunately, it does not install every gem successfully, even ones that are required for core IDE functionality (such as the
ruby-debug-ide gem required for RubyMine debugging to work correctly). You'd have to install such gems from the command line.
I'm sure I'll discover more things to comment on as I use RubyMine more. But based on my initial impressions and on other JetBrains products I've used, I highly recommend RubyMine for your needs and expect that you will enjoy it a lot.