Like all sectors, the government is inevitably moving towards web-enabled, "platform-based" models of delivering services to cut costs and improve services, he said.
However, Roberts said that in order to make this leap successfully the "public sector needs to force the issue with vendors".
"We will develop open APIs, a governance model, set open standards and encourage big vendors, who might prefer lock in, to comply to those standards," Roberts said.
"They might think it will never happen, but new vendors in future need to embrace open standards," he added.
Leeds City Council has adopted the Government Digital Service's design principles for services and requires all vendors to adhere to them, Roberts said.
In future government bodies could personalise the online services they offer citizens, he suggested, providing them with one single account to deal with all of government.
But for this to work, local authorities and government departments would need to agree common standards for data and formats, he said.
"We need to focus on information and interoperability. People could have a GOV.UK account with information sucked into it from all the services they deal with," he said.
"Across Leeds, if you can get the standards right, in future I'd love to get multiples of components developed by niche suppliers and combine them together," he said.
Roberts described the platform approach using an analogy with Lego bricks representing different individual sets of technologies.
"Government as a Platform enables you to pull together the right set of Lego bricks for your individual needs - it's how you enrol and enable a whole ecosystem to create solutions and innovations to fix our problems", he said.
For example, Roberts said this sort of approach could enable someone to create a transport app for Leeds, which pulls in live data on car parking spaces, the South Yorkshire Passenger Transport Executive, and data from the buses.
If it could also combine traffic data, that app could tell you the quickest way to get to work or which is the best car parking space for you, he said.
The Cabinet Office's efforts to adopt open standards across the public sector have already met with resistance from incumbent suppliers.
Microsoft lobbied against the adoption of the Open Document Format for government documents before it was finally agreed last July, encouraging employees and partners to oppose the move during a consultation in the months beforehand.
The company wanted its proprietary standard, used in Word, which is currently the main word processor in government, to be chosen instead.
The government hopes its adoption of ODF will make it easier to share documents between agencies and reduce dependence on expensive Microsoft licences.