ATpy (Astronomical Tables in Python) is a Python module aimed at dealing with tables of astronomical data with a common API. To date, the following formats are supported: FITS, VO, and IPAC tables, and SQLite, MySQL, and PostgreSQL databases
Project Galileo at Sourceforge.net aims to provide developers a unique opportunity to develop open source software for an on-line telescope for schools across the UK. See http://www.projectgalileo.org.uk for more details.