Allows you to define an external source for the Taxonomy Autocomplete field (i.e. a web service delivering a JSON list of Drupal modules, or an XML service delivering a list of descriptors from a thesaurus, or a SPARQL endpoint with RDF data). Multiple unrelated sites can connect to the same taxonomy. A local version of the term will be created and can be synced with the external term in the centralized vocabulary.
This is a complex project to allow frontend Aegir extensions to install extensions into the backend of Aegir too.
This will require the 6.x-2.0 release of Aegir, which won't be done for a while.
This project will have some interesting security implications, which will be documented; Unless you understand the code perfectly, I would suggest not installing this module until they are documented and you can decide if those security implications are worth it.
Why would you want this? The most common use case is when working in multiple environments with different URLs, like dev/staging/production. When syncing your production database with a test server, absolute URLs will redirect you to the wrong site. Also, if you're changing domain names, this will help prevent incorrect URLs.