MOM-CA uses and in some parts extends the [eXist application server](http://exist-db.org/). The source code extending or patching eXist is located under [my/eXist](../tree/master/my/eXist). eXist provides an interface to write custom XQuery modules extending the function library. Following this , MOM-CA implements a custom XQuery modules:
* an Excel module for the conversion of Excel sheets into XML
* a text difference module
* a text difference module which forms the basis to compare
All these XQuery modules are located under [my/eXist/extensions/module/src](../tree/master/my/eXist/extensions/module/src).
