I have been looking for a good text editor for Rails for quite a while. Actually I have found the ultimate one, it was not difficult, but it only exist on OSX and this is of course TextMate. I simply love it for its simplicity, great usability. It's superfast with an uncluttered interface and all the nice additions that make your coding life so easy. So with these high expectations it seemed to be a mission impossible to find something on Windows and Ubuntu.
On Windows we can look at some text editors like the Programmers' Editor but it does not really support the work with many files and also not so Ruby friendly.
I have looked at the most popular IDEs, like Netbeans which is a Java IDE and it was supporting Ruby until the latest 6.X.X version but the support has been discontinued and I have found Netbeans too heavy for the job. I prefer having my terminal windows and a lightweight texteditor open.
I checked out Aptana which I have been using before for HTML and PHP and I'm very satisfied with but somehow it did not impress me either.
Then I saw on some sites the name of Redcar which is a very funny name and I got interested as if it's red it must be Ruby And it is. Redcar is written in Ruby and runs on jRuby. It supports TextMate themes and snippets. It's extensible and runs on all platforms and have a lot of extra features which I haven't used yet. It's very lightweight, heavily supports the Rails code and very easy to work with. It's still in an alpha stage. You install and run it from the console/terminal after installing it as a gem. So Redcar is definitely my editor of choice. If you would like to try, download it at redcareditor.com