projecteuler.net tries to get you thinking about how to solve mathematical problems by programming. Here are the first five problems, solved in Ruby, including comments.
After editing some source files with different editors on different platforms, I had some troubles with automatically inserted tabs messing it all up.
This little script replaces all tabs with two spaces.
Lots of IDEs (e.g. Netbeans) and some editors (e.g. gedit with plugins) have a nice feature: They show comments, which start with something like TODO or FIXME. Those annotations are quickly written and they make it harder to forget some things you wanted to (or have to) do.
I have just discovered that Rails has this feature already built-in!
This article is written for people with experience in programming in general, but who are new to Ruby.
A German version is published in the offline magazine #2, a magazine by some students of TU Dresden.
The intention is to demonstrate some features of Ruby and show, what is so great about Ruby:
A clean syntax combined with the possibility to adapt the language to given requirements flexibly.