Synonym for extension

Question

In the following paragraph I talk about extension I am developing and I also mention PostGIS, which is an extension of PostgreSQL. It might be confusing so I would like to rename one of the two but I cannot think of anything better than "extender" which is still kind of the same word.

Being aware of these advantages, the main goal of this thesis is to design an extension that implements database storage for output data derived from geoprocessing services run within the PyWPS framework. They typically produce geographical data, so appropriate software must be used that is capable of dealing with this type of data. In this thesis, PostgreSQL is used together with its spatial database extender PostGIS. The extension is written in Python.

Answer 1

You are right, PostGIS is a spatial database extender for PostgreSQL and I would prefer to use the correct terminology. However you can move the second reference to your extension to the first sentence and it will remove the possible confusion, just like:

Being aware of these advantages, the main goal of this thesis is to design an extension, written in Python, that implements database storage for output data derived from geoprocessing services run within the PyWPS framework. They typically produce geographical data, so appropriate software must be used that is capable of dealing with this type of data. In this thesis, PostgreSQL is used together with its spatial database extender PostGIS.