If we (I and my friends) would like to build web-based products and sell it using a license approach (to renew every year for example). Which server-side language will be most suitable for our purpose?

We could target the following audience:

- Personal sites.
- Serious small-medium companies (to sell prducts such as Help-Desks, Forms,etc.)
- Restaurants (to sell online order web applications).

We would like to

- attract as many customers as possible.
- provide updates for our prodcuts (for our customers).
- make our products easy to use.

There are number of open-source frameworks and languages that has potential to handle our business problems (like Django, Python, Java, etc..) However, we are not sure which one is easier to learn and has variety of tools/plugins to help us in development process. Thus we need to get you experience on this hard to decide matter.

Which language and its supporting framework we should choose ?