GDS is the team responsible for the much anticipated GOV.UK website, which will act as a single domain for citizens to access services and information across government.
The team has been using Drupal as its CMS for many months, but decided to bring in Sirius to help it harness additional features, as well as get advice on its use of other open source technologies.
Sirius' CEO, Mark Taylor told Computerworld UK about the work he has been doing with GDS.
"GDS started working on Drupal themselves, but got a bit stuck and needed some help. Drupal is awesome, but it has a steep learning curve. It also has a bunch of modules, such as e-commerce and spam blocking, which GDS wanted to take advantage of," said Taylor.
"We have done some workshops with them on this, some strategic work, training courses, basically shown them the capability of Drupal and best practice."
Mark O'Neill, Head of Innovation and Delivery at GDS, said that the work with GDS is a good "example of how government and SMEs can work together to achieve successful outcomes".
However, Taylor did point out that although GDS is working in a way that government has been talking about for years, through its use of agile methodologies and open source technology, it still faces some significant challenges.
He said that GDS is pretty much open source "top to bottom", but still struggles with procurement and security assurance.
"One of the main challenges for GDS is its ability to procure open source technology. What the government needs to do is get more open source companies on the G-cloud framework, because the traditional route is too clunky and expensive," said Taylor.
The government launched its CloudStore in February, which saw 257 suppliers signed up to the G-Cloud framework and catalogued within an online portal. It is hoped that government department procurement costs will be cut down using Cloudstore, as it removes the requirement to tender for contracts.
Taylor added: "If they go down the tender route they are back in traditional territory of having to deal with large SIs and expensive contracts."
"The other problem is security assurance. There is still a prejudice that open source technologies can't be assured for government use, which just isn't true. CESG [the body charged with accrediting IT products] needs to make this a priority if the government wants more open source in Whitehall."
, it was recently revealed that the cost of GOV.UK is so far nearly five times lower than that of the existing site, Directgov.
Cabinet Office minister Francis Maude said in a parliamentary written answer that the budget for 2011-12 and the financial year to date of the GOV.UK, including its alpha and beta sites, is "approximately £4.6 million".
In contrast, the government revealed that Directgov cost taxpayers £21.4 million, or 11p per visitor, in 2010-11.