One of the most overlooked features of Java and programming generally, is WeakReferences. Here you can find a walkthrough of java.lang.ref and similar options in other languages with suggestions of possible uses.
A common task in most of Rails applications is to use internationalization. You have to work with yaml and text files to manage your web application translations. Sometimes, you need your system users to help you translating it to several languages. So, you need a user friendly and easy tool to translate your web application.
The web is moving to HTML 5 where SVG images are the standard images to use. But how to generate SVG images to include? You might draw static SVG images and include them in your web site but this will not help with generated SVG images with dynamic data. Of course, you can read the complete specification of SVG and generate your own images; these are a few hundreds of pages; good luck with that :)
If you are already using Heroku on your Mac or Linux with some email like email@example.com and you want change the currently active username on your Mac to other like firstname.lastname@example.org, you should do the following: