PortaBase is a database program for creating, browsing, and editing single-table data files. Notable features include the ability to change the columns at any time, views of column subsets, multi-column sorting, multi-condition filtering, CSV import and export, XML import and export, and column summary statistics. Typical uses are media inventories, reference charts, shopping lists, and TODO lists.
The cdcat is a graphical (Qt based) multi-platform catalog program that scans the directories/drives you want and memorizes the filesystem (including the tags of MP3s) and stores it in a small file. The database is stored in a gzipped XML format, so you can hack it, or use it if necessary. Cdcat can store the contents of some specified files up to a size limit if you want (for example: *.nfo).