I am amazed to discover lots of discussion about a so called "Open Source vs SaaS" debate.
Surely it is obvious that the barriers to adoption of SaaS and the fears about the uncertainty of provision of service will be reduced through greater patration(as in portability of service). The fastest way of achieving this is through providing an operational means of implementing an open standard - which means Open Source.
It is not a this vs that debate, as Open Source will accelerate the adoption of the XaaS stack and it is complimentary to it.
Next I'll be hearing about the great "Salt vs Vinegar" or "Fish vs Chips" debate ....
I'll have mine "Fish AND Chips" please.