Since upgrading to Eclipse 3.7, the Eclipse PDE plugin wants me to specify an \'API Baseline\' for all my Eclipse Plugin projects.
However there seems to be no documenta
API Baseline are intended to help you maintain plugins that others can use. The API Tools help you create compatible API versions. Follow the link that Sumit Singh posted to get an explanation on how to use them.
If you develop a plugin just for your personal use and are not interested to maintain a compatible API, you can follow the advices to disable the warnings.
When you develop plugins for a community, e. g. the eclipse plugins themselves, it is essential that you keep API incompatibilities to a minimum. Then you will follow the advice and set the baseline to 4.2 when you develop for 4.3. The API tools will help you make 4.3 an enjoyment for all current 4.2 users.
Please note, that the API Tools are for the developers of the plugins that will be used by others. They are not addressed at the users of those plugins.
Take a look may it helps you:
From the PDE API Tools User Guide:
An API baseline defines the state you want to compare your development workspace bundles against for the purposes of binary compatibility, bundle version numbers, and @since tags. For example, if you are developing bundles for Eclipse 3.4, you will use Eclipse 3.3 as your baseline.