Although initially starting with no support for Java, platform providers had shown an interest in Java at some point later on.
Developing on the Force.com can be done in a browser, via a set of forms. Complex business routines are implemented in text boxes, and code integrity can be checked.
The other alternative is with the Force.com IDE that is based on Eclipse. It offers code completion. As the code is deported to the developers machine, it permits collaboration, just like any classic development project.