The first public release of OpenGuides occurred on 29 April 2003: https://metacpan.org/source/KAKE/OpenGuides-0.04/Changes

So I think this calls for a celebration on or around 29 April 2013! Given current patterns of activity, I suspect doing this in the UK is the most sensible option. (I can offer accommodation for non-UK people.)

I'm on holiday in Moreton-in-Marsh between 24 April and 1 May, so if we're going to do this on the weekend before the anniversary (i.e. 27-28 April) then Oxford would be the most plausible venue.

If we do it the weekend after (i.e. 4-5 May) then we could do it either in Oxford or in London.

Thoughts?

Kake