Back to basics – new Greenfoot video

Recently, I have announced the first Greenfoot tutorial video. Not an overwhelming success as yet (no nominations for Academy Awards or Emmys, no calls from Warner Bros. or the BBC). As far as I know, maybe not even a viewer yet… Alas, I shall not be discouraged. If nothing else, it gives me somthing to look back on in a few years and laugh at how funny my voice sounded…

The idea with these videos is to provide random tips and techniques of doing various things in Greenfoot. However, equally random as the choice of subject for these videos is my order of producing them: I started with “Making explosions” – a rather advanced tip for blowing things up. Not really the first thing you need to know when getting started with Greenfoot.

The idea is, over time, to build up a collection of short tutorials that cover a broad range, from basic tips to more sophisticated techniques. The order in which they will appear will, however, remain somewhat random. I record them according to whatever I happen to have on my mind at the time.

I realise, though, that the basics — getting started — is really what most people need to know right now. So I have recorded a first general introduction. Not really a programming tip, but a very quick overview of what Greenfoot is and what it can do for you. So if you are one of the great majority out there who haven’t got a clue what Greenfoot is, here’s a thing for you to look at and find out.

More to come in the near future.

Making explosions – a Greenfoot video demonstration


Many of you probably know that I am working on the Greenfoot project. The software itself is in public release and is very usable. What is lacking at the moment is documentation – good instruction that tells people how to do things.
Creating this documentation will be one of our main tasks over the coming year or so. This will take various forms – web pages, a book, work sheets, examples, videos…

I have decided to make a start with some videos. They will be slightly random in order, showing things which I happen to have on my mind. Over time, though, I hope to build up a collection that is somewhat ordered: starting with basic tasks, and moving on to more sophisticated things.

So, here is the first batch: it shows you how to make a nice-looking explosion in Greenfoot. The video tutorial is sliced into three parts, just to keep the file size manageable.

The Greenfoot Video Tutorials

Making Explosions, Part I (length: ~5 min, 11.6 MB)
Making Explosions, Part II (length: ~18.5 min, 57.9 MB)
Making Explosions, Part III (length: ~15 min, 52.2 MB)

These are all published under the Creative Commons Attribution-NonCommercial license.

You can also get the source code of the project developed in the video.

Have fun. And let me know if you turn this into an interesting Greenfoot scenario!

Every open system develops towards the unusable

Kathy Sierra, on her excellent blog (which may have very sadly come to a close now, but that’s another long and sad story) has recently published a collection of her favourite graphics from the last few years.

Here is one that I really like:

(By Kathy Sierra, from,
shamelessly copied without permission – I hope she doesn’t mind!)

You should really look at the site yourself – there are many more great diagrams!

The Featuritis diagram above struck a nerve with me, since it’s something that’s been close to my heart for a long time. It is also related to what I think is one of the Natural Laws Of Software Development:

Every open system develops towards the unusable.

If you want to find out why I think that, read on.

Continue reading