When talking about mobile software development lots of people forget about the fact that it's not only the native programming language that can be used on a given platform. I've read a lot of comparisons between Symbian/C++, Win32/MFC/.NET of Windows Mobile, Objective-C on iPhone, Android, etc. lately discussing the advantages and disadvantages of these options, maturity and popularity of the underlying platforms, probability of writing successful programs, etc.
- Java - Mobile Java (JME) has been available since the early days,
- Flash Lite - Adobe's Flash has been added to S60 phones 1-2 years ago,
- Python - Python for S60 is an open source initiative enabling rapid application development,
- Ruby - Ruby for Symbian is one of the newest additions to S60,
- .NET - Red Five Labs's add-on to S60 platform is tempting Windows Mobile developers to use their skills on another platform,
- NS Basic - Powerful development environment and run-time framework for programs written in BASIC (link),