OSGi - introduction

OSGi - Open Services Gateway initiative helps to develop and deploy applications/libraries which are modular or need to be modular.This specification was started by OSGi alliance in 1999.
To develop OSGi application, the OSGi specification defines two things: first the set of services that the OSGi container needs to implement and second a contract between the OsGi container and the application. So in short, you need a OSGi container to run your OSGi complaint application. As of now there are 3 containers that are OSGi complaint; Knopflerfish,Equinox and Apache Felix.
OSGi offers several advantages

1. one can install,uninstall,start, stop any modules of the application at runtime.
2. Helps to build service-oriented applications
3. Application can have more than one version of a module running at the same time.

In the next article I will show you how each of these advantages translates into code rather than just plain english sentences in your tech vocab.