S40 is a platform for mobile phones that run Nokia's proprietary operating system. Most people refer to S40 like an operating system. I will be focussing only on S40's user interface (UI) in this blog entry.
The last S40 phone I got for myself is the Nokia 6230b and it used a modified version of the S40 2nd edition platform. It's modified because it was the first S40 to use a grid for the menu. All future S40s have the option of grid or list for the main menu. My last review, of the Nokia 3555, made me think about how much S40 has progressed since late 2004 against the latest S40 5th edition.
One very observable difference between S40 2nd edition and S40 5th edition is the support for portait screens (128x160 pixels) instead of the old screen screen (128x128 pixels).
I love pictures and they truly say a thousand words. Now let's look at some screen shots (I switched the positions of the 6230b and 3555b a couple times just to make sure you pay attention - ok, I took the photos in two different sittings so I apologize):
Standby Screen (2nd on left, 5th on right):
You can do much more on the 5th's standby screen like control your music player, show calendar updates, and shortcuts to your most used apps.
Menu (2nd on left, 5th on right)
Not much has changed here except you can now see battery life, reception, and other indicators too. You can see these indicators without the phone now in all submenus.
More Icons (5th on left, 2nd on right):
There are some icons beside the text for help. Even though there is more vertical screen space, it hasn't increased the number of menu items on the screen at once.
UI Changes (5th on left, 2nd on right):
The left/right toggle for the 5th edition reduces the number of clicks, somewhat.
Some new icons don't match the rest of the User Interface (UI):
Some menus have an added Save button so some changes are not automatically saved. The icons don't match the look of the rest of the UI.
Real Theme Support (both from 5th edition):
The 2nd edition only support color changes while the 5th edition supports background and color changes. It's pretty neat that S40 will preview the theme after highlighting it.
Calendar (2nd on left, 5th on right):
Things that were good before are the same.
Calculator (2nd on left, 5th on right):
The calculator has undergone a dramatic change from being a simple native app to a complex Java app.
Camera (5th on right, 2nd on left):
Much more controls on the camera application like zoom.
One thing I wish S40 had was a way to switch between an Advanced mode (for users to configure the phone) to a Basic mode. I usually recommend S40 phones to people who want a phone for a phone and a no non-sense phone UI. But with so many available options and customizability like active standby, S40 is starting to become overwhelming for a first time user. I wish there was a way I could set up and customize the phone for the user in Advanced mode then switch it to Basic for them to use. The only other option I can think of is to refer them to emerging market phones but they're hard to come by in North America and/or cost more than carrier subsidized phones.
The new S40 operating system puts up a good fight against Sony Ericsson's phone platform in terms of customizability; but I don't think Nokia's S40 platform is as refined judging by the inconsistencies in the UI look.
Nokia has made great strides to make S40 a highly customizable platform without needing to make it a smart phone operating system. However the introduction of all these options have made S40 a lot more overwhelming for a first time user than previous iterations. I personally like how the new UI works and the additional functionality it provides and I'm sure users will slowly get accustomed to it even if they're a first time user.
You can learn more about the S40 platform at Forum Nokia