Richard: When did you first consider .NET Compact Framework support for Symbian devices?

Dušan: I've been watching the mobile space for some years, from the release of the Ericsson R380. This first Symbian device, as you know, was closed. At the time Java was the main programming language available for developers who wished to create mobile applications. My background is as a Microsoft developer. For many Microsoft developers, like myself, Java was not ideal. Similarly when open Symbian devices became available, Symbian C++ was not a good option either, because it does not allow us to leverage our existing Microsoft development language skills.

So I'd always wanted a better way for Microsoft developers to take advantage of Symbian. When Microsoft submitted key parts of the .NET specification to ISO for consideration as a standard, this created the opportunity to implement a Microsoft development language for competing operating systems. I realized that Symbian could be one of these operating systems and the idea of enabling .NET Compact Framework for Symbian devices started there.

Richard: Did the work start in 2005 with the formation of Red Five Labs?

Dušan: No, we actually started a proof of concept during 2002 and 2003.

Richard: What drove your decision making in picking S60 as the initial target platform?

Dušan: S60 was the closest Symbian platform to Microsoft Smartphone. When you are developing in Microsoft Visual Studio you target your application either at Pocket PC or Smartphone (as they were originally called). The Smartphone profile doesn't use as many features as the Pocket PC profile of .NET. For example, it drops a number of features such as the data grid and there are no buttons. This meant there were fewer APIs we needed to implement. So with S60 we had a smaller set of APIs and class libraries to create. In addition, S60 has a very good market share, which was a significant motivation as well.

Richard: The Mono project is working to provide .NET support on Linux. You make reference to this on your website. How important was this project in enabling what you have done?

Dušan: Our product consists of class libraries and a runtime. The runtime was written from scratch by us for S60. So we haven't used Mono in any way for the runtime. However, for many of the class libraries, particularly those that don't have any platform dependency - things like managed code and C# libraries -we used a number of class libraries from the Mono project. We removed the features not found in the .NET Compact Framework to keep the code at a manageable size. Since then the code base has diverged considerably, as we've added code to optimize performance on Symbian devices and leverage parts of the Symbian OS that are different or don't exist on Microsoft Windows Mobile or Linux.

Richard: On another blog entry it suggested that you took longer than expected to get your preview finished, what were the reasons for that?

Dušan: I think in general we always feel we are further behind than we would like to be. Microsoft is pressing ahead with .NET Compact Framework version 2 and version 3 is not that far away. At the same time Symbian OS 9 has become available during our development. So both the technologies we rely on are developing rapidly and it's hard to keep up with the advances in these technologies.

If there was one area where we underestimated the amount of work involved, it was in the QA and testing. It's not easy to automate testing on a Symbian emulator or a device, so that part of the project has progressed slower than we would have liked. Apart from that, there been some things that have been harder to do than we expected and some things that were easier.

However, overall the comment on the blog is really more to do with the fact that we would like to be further ahead than we are, rather than any specific technical issues.

Richard: What is your target market: third-party developers, handset manufacturers, or perhaps operators?

Dušan: We are currently focusing on third-party developers in the short to medium term. Beyond that we hope to form relationships with the manufacturers of Symbian smartphones, with a view to distributing the runtime on their handsets.

Richard: What will the final production product deliver and at what price?

Dušan: In our first product we going to distribute the runtime bundled with a set of tools for around one thousand dollars. The runtime will then be available for developers to distribute with their applications at no extra cost.

We decided to do this because, when we looked at the market, we saw that a per-runtime license fee could constrain the uptake of our product. We saw Appforge for example and the frustration amongst developers at the runtime per handset charge. While this may not be an issue for many of Appforge's customers, particularly those targeting the enterprise market, for a third-party developer it is. Adding the cost of a per device runtime license makes an application uncompetitive, when compared to Java or Symbian C++ developers who have no license cost per application. So we realized that we couldn't add a per device license royalty. So we will charge a one-off per developer license fee and allow the runtime to be distributed free of charge.

This means we are leveraging our runtime to sell developers tools. These tools will provide better integration with Visual Studio for developers targeting their .NET applications at Symbian devices.

We feel this will be a competitive package and in-line with what developers are already paying for similar tools, such as Visual Studio. At that price our tools will be within the reach of many developers.

Richard: As the promise of your framework is to allow developers to run unchanged .NET Compact Framework applications on Symbian devices, exactly what tools are you providing?

Dušan: In a perfect world there wouldn't be any tools needed by a developer to move their .NET Compact Framework application to a Symbian device. However, there are many things which make the process less than straightforward.

For example, very few developers create pure Compact Framework applications. Many applications tie into the native operating system and use platform APIs using the .NET service Platform Invoke. So a developer may use the vibration API in their Windows Mobile application and want to use the equivalent feature from S60. So there needs to be some sort of conditional compilation when the application is built for Symbian.

Another example is the way in which applications are installed. In Windows Mobile developers create a .cab file to do the installation, while for a Symbian phone they need to use a SIS file. Then, when we provide S60 3rd Edition support, there are the application signing requirements and Symbian Signed, if the developer wants or needs to take that route. So developers would find it useful to have tools to take their Compact Framework application and produce an installable SIS package for Symbian phones.

Then there is testing, developers will want to be able to run their application in the S60 emulator, this is not currently integrated into Microsoft Visual Studio. A managed debugger would also be very useful.

Our goal is a situation where a developer creates an application in Visual Studio and then simply selects S60 as the target to fire up the emulator, start the debugger, or package the application. We hope to work towards a truly integrated experience, but we're not there yet.

Richard: Your preview product is for S60 2nd Edition, are you planning S60 3rd Edition support?

Dušan: Support for S60 3rd Edition is very high on our priorities list. The feedback we're getting from Symbian and Nokia is that it is essential even for a version one release. There is a lot of work to do, as Symbian OS v9 has a lot of changes in it. In addition, new devices such as Nokia Eseries devices will be very important for .NET developers. As a result we are working towards providing S60 3rd Edition support in our first full release.

Richard: Have you explored how platform security and Symbian Signing will affect you?

Dušan: That's certainly an issue and we have had discussions with Symbian about what needs to be done. Fortunately we won't be the first to do this, as Appforge provides a reference example. It's going to be somewhat challenging, but we are prepared.

Richard: Any plans to provide UIQ support?

Dušan: UIQ is definitely on our radar, but probably not in the version one release timeframe. We are currently deciding whether to support Compact Framework 2.0 first or UIQ. UIQ is analogous to Pocket PC so it's going to involve adding support for a number of additional interface paradigms, such as the stylus and group buttons. It's a significant amount of work, but once we have a stable runtime we will definitely go ahead with UIQ. We have also had some initial interest from Sony Ericsson, I think they would like to see .NET running on their handsets.

Richard: I would imagine there would be a lot of interest from Symbian and its licensees in this technology. How would you characterize your relationship with companies like Nokia?

Dušan: We don't have the same close relationship with Nokia as we do with Symbian. We have a formal partnership with Symbian, through the Platinum Partner program; we don't have a similar relationship with Nokia. However, there's certainly been interest from Nokia in our technology. They have been asking questions about our technology's performance, our long-term strategy, our proposed licensing, so there seemed to be interest in what we're doing. Given where we are in the development cycle it's somewhat premature to engage in specific talks. In addition, particularly at trade shows, a number of manufacturers have expressed interest and asked to be kept informed of developments. Taking things further probably depends on S60 3rd Edition support; hopefully it will be the key.

Richard: You have also taken this technology to the Microsoft Embedded Developers Conference, what has the reaction been from Microsoft developers?

Dušan: I think most Microsoft developers creating mobile applications are aware of Symbian and would like their applications to run on a broad set of Symbian devices. A Symbian developer will already have made a choice of using C++ or Java so is unlikely to consider .NET. A Microsoft developer who is using .NET is very unlikely to want to learn Symbian C++ or Java. So our technology is a good opportunity for them, opening up a big new market for little cost. However, Symbian is not at the front of US-based Microsoft developers' thinking, if only because Symbian devices have a low market share in the US. I'm sure that's set to change though.

Richard: Symbian and Nokia have recently announced support for a range of standard C APIs. Would this technology have made your development easier?

Dušan: P.I.P.S. and Open C might have offered some benefits. However, as we developed the runtime from the ground up for Symbian, even if those technologies had been available, I think we would still have been more comfortable using the native Symbian APIs. These technologies would have certainly have had little impact on the development of the class libraries.

Richard: Is this technology a threat in any way?

Dušan: Open C and P.I.P.S. are a great initiative and good for the platform. I don't see them as a threat, simply because a developer who codes in C# or Visual Basic is not likely to want to write in C. What it does say to us is that Symbian is quite open to multiple development technologies on their OS. As the platform becomes more open, in a genuine sense, the more likely I think it will embrace our technology.

Richard: What was the reason for releasing the preview product for S60 2nd Edition?

Dušan: In a word, feedback. We want to hear from developers about every aspect of our technology: is our pricing and the tools model right; should we be supporting UIQ; have we made the right trade offs in supporting .NET features. We want any and all feedback. We want to provide .NET developers with a tool they can really use, so as we move towards commercial release feedback will be shaping the final product and our future plans.

The preview release of .NET Compact Framework for S60 is available now from http://www.redfivelabs.com/content/download.aspx.