Complex sentence: Celtix developed by IONA Technologies (acquired by Progress Software in 2008) and XFire developed by a team hosted at Codehaus, combined by people working together at the Apache Software Foundation.
Split into simpler sentences: Celtix developed by IONA Technologies (acquired by Progress Software in 2008) and XFire developed by a team hosted at Codehaus. These two projects were combined by people working together at the Apache Software Foundation.