I have just bought a MacBook for some ruby development and like the look of Aptana Studio as a really nice IDE.
The question I have, however, is that I want to know (before getting too deep into it, and potentially wasting time) is can I create plain old .rb files without the rails framework attached? Also, can I execute the ruby file straight from the IDE, or will I have to use Terminal?
As I said, I am only just learning Ruby and I am working through some books I have bought, and while I do wish to get into rails soon, I feel its important to learn the language properly, before asking rails to do a lot of stuff for me.
Any other thoughts on best practices and other potential IDE's would also be appreciated.
I'd recommend Netbeans (Ruby Edition obviously) or Jetbrain's RubyMine over Aptana. I've had issues with Aptana and Ruby when I tried it. Rubymine is still in public preview release status, but it will be a paid product when it's released in a month or so. It's developed by the same people who made IntelliJ IDEA. Netbeans actually works very well with ruby and rails and it's free. Both allow you to execute ruby from within the IDE and have rails support.
I've also found irb very useful, Netbeans allows you to run irb from within the IDE as well. Having code completion and inline documentation helpful when starting out.
For just fooling around with Ruby I suggested an editor, the command line, and IRB. You will have more fun and learn more, quicker.
After that, get into IDEs and Rails and all the complexity that comes with them.
Yes, you can create plain old ".rb" files inside RadRails or Aptana Studio, and they don't have to be inside a Rails project or "attached to the rails framework". You can also run or debug a ruby script inside the IDE by right-clicking the file or inside the editor and choosing one of the Run As > Ruby Application or Debug as > Ruby Application entries. With Studio 3 you can even run them from an embedded Terminal view. RadRails 2.x had a Rails Shell where you could run or debug files from a command-line interface as well.
As the developer on RadRails, I'm a bit biased - but I would agree that users should be pretty familiar with using the command line whether they decide to use an IDE for daily programming or not. And of course, having an interactive REPL like irb to play with is another useful tool in getting started. Heck, you can even just use the online one first before installing ruby: http://tryruby.org/
