Adoption of open source business intelligence software is doubling every year because the products are viewed as "good enough" for routine applications, according to a recent report by Gartner analyst Andreas Bitterer.

Commercial BI software vendors still have superior BI technology, she wrote, but "open source is slowly becoming just another sourcing option for everyday BI requirements." No longer just an option for cash strapped organisations, open source BI tools are going mainstream, Bitterer said.

Gartner cited five open source BI organisations in its report: Actuate, Jaspersoft, Jedox, Pentaho and SpagoWorld.

Though the downloaded software is free, Bitterer said the cost of large scale open source BI deployments can still hit "the million dollar range" thanks to high development and labour costs on top of support subscriptions.

Gartner urged CIOs to scan their local talent markets to make sure there are developers who are skilled with open source BI tools. Otherwise, a lack of trained developers will slow the project and increase overall costs.

Some commercial BI vendors have noticed the encroachment on their turf and are countering by offering free "starter editions" of their software, the report said.