The system will help the councils deliver joined-up working across departments and meet requirements outlined in the Children's Act to share childcare records across agencies.
GPs, social workers, mental health workers and the police will be able to access the system, based on CareWorks' Raise product.
Ceredigion County Council went live with the system last week, and the Bridgend, Blaenau Gwent, Gwynedd, Isle of Anglesey, Powys and Torfaen county councils are expected to go live in the coming months.
The system is built on Microsoft .net technology that will enable applications to be accessed via intranets or the internet. The web services technology will allow the system to link with existing applications in a variety of agencies, said Michael Dolan, director at CareWorks.
The Welsh Assembly provided funding to help seed the development of the consortium, in which professionals from each authority came together to map out the specification for the system requirements. The Welsh Assembly then paid KPMG to research the market to see if there were off-the-shelf products that could meet the specifications.
Although no products fitted exactly, CareWorks agreed to develop its Raise software to fit the councils' needs. "The aim is to use that as a basis to change and enhance our own product," said Dolan. "Councils had input on the project team and we will use it in other systems in the UK, so other customers will benefit from this."
Tony Garthwaite, director of personal services at Bridgend County Council, said that information management had been a source of frustration for social services staff.
"We were not in the vanguard of sharing information," he said. "However, Wales is increasingly different from England in local government, and unitary authorities allow a more coherent approach."
The system will also be able to switch languages between Welsh and English, which required system interfaces and forms to be redesigned.
Dave McGregor, assistant director of personal services at Bridgend County Council, estimated that economies of scale and joint working with the software company could save each council £50,000 in initial capital outlay and £30,000 in ongoing costs.