eXist-db is an open source database management system built using XML technology. It stores XML data according to the XML data model and features efficient, index-based XQuery processing.
This tutorial shows you how to feed data directly from a Google Spreadsheet rather than from a file. The advantage of this is that you can edit your data in Google Spreadsheets' user interface. Here is an example.
Tokyo Cabinet is a library of routines for managing a database. The database is a simple data file containing records, each is a pair of a key and a value. Every key and value is serial bytes with variable length. Both binary data and character string can be used as a key and a value. There is neither concept of data tables nor data types. Records are organized in hash table or B+ tree.