Most develop companies use to choose a development platform for all its projects. While this is probably not a good idea for big ones, I realize than doing so has some advantages for small ones. Get specialized is important in order to achieve the best productivity.
There are several platforms you can choose:
The first two are the ones most companies choose. Probably the most important features for those are they are quite extended, it’s possible to develop for a lot of devices, has great IDEs, etc.
I would like to mention that Python at this level. Since Django became important in the web applications scenario, developers coming from PHP, Java and others has given it a chance, you can develop desktop applications (QT, wxWindows, etc.), web applicatrions (Django, Turbogears, etc.), mobile applications (PyS60, PythonCE, etc.). There are some IDEs such as Eclipse and Netbeans (6.5 or greater).
Python is much more faster to develop than Java (and probably .Net) as you can perform quite complex operation in a really simply manner, while it keep the code clean and readable due to its blocks (not like Perl).
On the other hands it miss namespaces (can be simulated some way using packages) and private variables.
On my view Python is one of the most interesting alternative to the major established develop platform.