New Zealand's largest open source IT company Catalyst IT has bought Christchurch firm Egressive after the small firm sought to be part of the much larger operation.

Egressive has large clients such as Cera (Canterbury Earthquake Recovery Authority) and Scirt (Stronger Christchurch Rebuild Infrastructure Team) to recommend it and approached Catalyst IT to see if it was interested in buying it.

"We were very gratified that they did," Egressive founder Dave Lane said.

The price paid is confidential.

He and his business partner Rob Fraser felt the small team of six staff had achieved as much as they could based in Christchurch for 14 years and wanted to tap into the greater level of government work that Catalyst had in Wellington and elsewhere.

Egressive provides the technology behind the websites of Cera, Scirt, CCDU (Christchurch Central Development Unit) and NZTA (New Zealand Transport Agency).

Catalyst, headquartered in Wellington, has 150 staff across New Zealand, Australia and the United Kingdom.

Open source software allows users to modify it to suit their businesses and services and to distribute it to others.

By contrast proprietary software is restrictive on who can use and requires users to purchase licences.

Catalyst IT strategy manager Jason Ryan said Catalyst and Egressive had shared values, had worked together and were part of the open source community.

Catalyst could offer Egressive staff a broader range of jobs and peer group to work with. Catalyst had already an established relationship with Egressive and this would not be a dramatic change.

- © Fairfax NZ News