My Background: I've had a number of customers request various integrations involving QuickBooks. I have a good deal of integrations experience, whether connecting custom applications to SAP backends for major insurance companies, connecting various Hospital Information Systems (HL7) or connecting SaaS applications via APIs for smaller businesses. I've been a manager, architect and direct implementer in all of those projects, so I have some experience in the arena of integrations.
Intuit's various integration platforms are some of the most opaque I have ever run across. If you want to integrate with QuickBooks, you first have to choose between 3 or 4 different possibilities, and choosing isn't easy. Especially when Quicken pushes their Flex-based platform above the other options, and I don't want to use Flex.
I've spent countless hours reading through documentation, picking through open source libraries and always came to the conclusion that an integration with QuickBooks would either require a client with deep pockets or a healthy war chest that I could spend on development. Development which would probably pay off down the road, but which would amount to sunk costs for some time, while working out the intricacies of the integration.
So, Intuit has a ton going for them - most of all a huge customer base. But unless they've considerably slimmed down their integration platforms and made them more accessible, they're shutting a whole host of potential integration partners out.
Meanwhile, Xero's breathing down their neck





