European and US businesses remain concerned about the security of open-source software, according to new data from Forrester Research.

Fifty-eight per cent of the large companies surveyed said they had security concerns about open source, while the figure for small and midsized businesses was slightly higher, at about two-thirds. Within those groups, only nine per cent of enterprises said they were "very concerned," compared with 45 per cent for the SMBs.

More than half of SMEs (57 per cent) also expressed concern that open-source software would be complex and hard to adopt, but only 32 per cent of enterprises expressed a similar sentiment. In addition, 68 per cent of SMEs cited the availability of service and support for open-source software as a concern, compared with 47 per cent of enterprises.

The findings are among a wide range of data Forrester collected for two reports, "The State of SME Software: 2009" and "The State of Enterprise Software: 2009."

Meanwhile, security concerns over SaaS (software as a service) seem to be diminishing among companies large and small, according to Forrester.

The research firm polled a subset of SMB respondents who indicated they weren't interested in SaaS. Twenty-seven per cent named security as a factor, compared to 57 per cent in a 2007 survey. A similar poll of enterprises saw 31 per cent cite security concerns with SaaS, down from 47 per cent in an earlier study.

Forrester polled 2,227 IT executives and technology decision makers in the US, Canada, Germany, France and the UK between December 2008 and February this year.

Full security coverage is provided in the CIO UK Security Tech Toolkit