SaaS and Dependency Injection

Lately, I've been working on Spring.NET to figure out the possibilities of DI-SaaS relationship. Since we all are talking on Software as a Service thing, let's try to understand the requirements.

First, we need software components to be used as a service, those components should satisfy some requirements. The re-usability is the key, but it is not enough to have a generic/common design. Re-usability relies on dynamic configuration at runtime.

Second, Software components should expose their functionality over standard mechanisms. Thus, any type of configurable software component could be able to use them.

Third, configuration on-the-fly shouldn't require you to go back design-time. Which, configuration itself should be self-configurable.

Therefore, It's better to use Spring kind-of (pico or Avalon, too) framework to make it easy to interchange your components into service elements. This is my tought of course, but if you read MFowler's famous article on DI/IoC you can see for yourself.