A potted history … dates may be off a little, would welcome the true dates if anyone has better data
open.gov – 1994 – hand coded HTML (OGC hosted and operated) (original version said 1998, thank you for the update)
ukonline.gov.uk – 2001 – bespoke code with a database (BT hosted and operated)
ukonline.gov.uk – 2002 – open source clone of the original (Eduserv hosted and operated)
ukonline.gov.uk – 2002 – new design along with user centric approach – Vignette CMS (Sapient/Loudcloud)
direct.gov.uk – 2004 – significant user involvement, pan-government involvement – custom coded CMS (Sapient/Loudcloud)
direct.gov.uk – 2007 – clone version of the original, subsequently enhanced – Stellent CMS (Steria) (original version said 2006, thank you for the update)
alpha.gov.uk – 2011 – custom code integrated with extensive open source
beta.gov.uk – 2011? – assumed to be as above
gov.uk – 2012? – ?