NDAD is the UK National Digital Archive of Datasets. This project contains the source code for the bespoke software which drives the public website and many aspects of the data curation/archiving process.
RePEcPHP is a free PHP and MySQL based web interface to maintain a RePEc archive. The RePEc project (www.repec.org) provides a volunteer-driven public-access database of more than 100,000 working papers in economics plus other items.