Sounds like:
- C++
- Java
- Flash Lite
- Python
There are several runtime environments with different programming languages available on Symbian OS. Symbian C++ is the native language of Symbian because the operating system itself is written in Symbian C++. Additionally, Java is also included as the most common runtime environment on mobile phones. More recently, Flash Lite, the Web Runtime (widgets) and Python have been added to the mix. Whilst all of these runtime environments have their strong points, they also have some disadvantages and none is optimal for all purposes. To benefit from the advantages of different runtime environments, two runtimes can be combined in one project.
Taken from here.
EDIT: Sounds like maybe there are a few others too.
EDIT 2: See also the Wikipedia page:
[In addition to Symbian C++,] Symbian devices can also be programmed using Python, Java ME, Flash Lite, Ruby, .NET, Web Runtime (WRT) Widgets and Standard C/C++
