ImportX allows you to quickly create or batch update resources from direct CSV input, or uploading data files in a certain format. As of 1.1 the ability to use different formats (CSV, XML etc) has been built in - however there are no processors for formats other than CSV - I very much welcome contributions!
Download through Package Management and run the installer. Alternatively, you can download the package from the MODX site, upload it to your core/packages folder and add packages with the search locally option.
New in ImportX 1.1.1
ImportX 1.1.1-pl (January 29, 2014)