This is the first in a two part exploration of the making of Skype 4.0 for Windows. It offers a bit of an insight into the way things work here at Skype, and gives an idea of what’s to come. Look out for the second part tomorrow.

The rationale for 4.0

Online communication has changed significantly over the last ten years – both in terms of the way people do it, and in terms of who’s doing it. Voice and video calling, as well as instant messaging, are now firmly in the mainstream.

Despite this, the current generation of online communication tools have remained largely unchanged since the mid-1990s. The vast majority of instant messaging software, for example, has always looked and behaved very similarly – and, until the release of Skype 4.0 for Windows, Skype was no exception.

Of course, this has been done partly with good reason – there are familiar, established user interface metaphors which make software easier to use, and which lower barriers for new users. However, through our initial research, we began to discover that the way people use software like Skype is fundamentally different to the way people used instant messaging software back in the mid-nineties.

And that’s where it all began

In May 2006, we kicked off the project that has become Skype 4.0 for Windows. Skype had become much more than what our Director of Product Strategy, Mike Bartlett, affectionately describes as ‘a little chat on the side with your mates’ – Skype conversations had become an experience in and of themselves.

The number of people making Skype video calls had grown so dramatically since we introduced video in 2005, and we figured that they were going to be increasingly important in the years to come. Currently, over 25% of Skype calls include video, and with around 300,000 concurrent calls at peak times, that’s a lot of video. So, rather than continuing to patch new features – including video – on to a design (and design metaphor) which was arguably already 10 years out of date, we decided to start from scratch.

At that point, we set about asking ourselves serious questions about how to approach the development of the next big release of Skype for Windows.

Exploration

The first eighteen months of the process were very exploratory. We spent a long time experimenting with various designs, designing prototype after prototype, and running usability tests to see what worked and what didn’t.

We learned a lot about how people behaved with computers, and were surprised to find that the vast majority of people focused on one window at a time when using software like Skype. We spoke to usability researchers at other leading software companies to confirm our own findings, and the consensus was that the vast majority of people really struggled to manage an app across multiple windows.

Stepping up the pace

In late 2007, we began development work in earnest. Rather than setting ourselves a big final target, we worked in month-long chunks, experimenting with different ways of doing things with each iteration and sharing the resulting alpha builds of Skype 4.0 with employees for testing.

This gave our engineers and designers an opportunity to react quickly to feedback, experiment and re-release over and over again until we were comfortable releasing the first public beta of Skype 4.0 into the wild in June 2008.

Then began an intensive process of data-gathering, surveying, re-designing and re-engineering – but that, as they say, is a story for another day…