I am trying to migrate from Adacore's GPS to the Eclipse based GNATBench. GNATBench is available here for free download, but is packaged as a zip file. I have only installed Eclipse plugins through the marketplace, or through an online repository. I have tried extracting the folder into the Eclipse plugins folder, but it did not work. How do I install this plugin manually through a zip file? Is there another way of getting it?
Open Help > Install New Software... and click Add (top right).
In the Add Repository dialog that is shown click Archive... and select the zip file you downloaded. Also give the Repository a name. Click OK.
The Available Software dialog should now show you the contents of the zip and you can choose what to install.
来源：https://stackoverflow.com/questions/23199245/eclipse-manually-install-plugin