And they're not too enamoured with software as a service either...
The hidden cost and complexity of open source is still a key barrier to adoption for many CIOs and large enterprises.
Ian Cohen, Associated Newspapers CIO - and recently voted one of the UK's top 50 CIOs - said at the Forrester IT Forum in Edinburgh this week that open source just isn't "particularly relevant".
Cohen said that while he doesn't mind it being embedded in hardware or exploited by suppliers open source isn't something he is interested in doing himself.
He said: "It is another layer of complexity."
Daryl West, Lloyds TSB CTO, speaking at the same event agreed: "If you look at the savings you end up having to create a support organisation internally to support it. If you do the analysis fully it's not as attractive as is first apparent."
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The much-hyped software as a service (SaaS) trend also came under fire and Cohen said he remains to be convinced about SaaS in the enterprise, despite some of the services players such as Google have released.
He said: "It's a concept I'd like to buy but I'm a cautious buyer. I'm struggling with the next step, the industrialising of the idea."
Lloyds TSB's West added: "For large enterprises where you have got a lot of stuff, and an industry like mine tightly regulated, having core pieces of your application stack as a service doesn't fit. Then you've got to plumb it in and that plumbing is not easy."
But Pascal Matzke, principal analyst at Forrester, said the IT "ecosystem" will move more and more towards delivering functionality as a service through SaaS, storage-on-demand and adaptive IT services, with the CIO becoming a "service broker".
Matzke said: "Essentially what we are looking at is the concept of a service broker organisation to broker internal and external service delivery in the context of business service level agreements and on an as-needed basis. Technology will be much more transparent in terms of the value it provides to the business."
The key roadblock to all of this, he admitted, is the existing "silo" structure within many organisations' infrastructure and applications.
He said: "If you look at the monolithic application landscape, especially on the ERP side, consolidation is essential. That's going to take some time."