Open source has many allures: no licence costs, a wide range of support venues and the ability to work directly with code for customization or quick repairs. But it can create IT headaches, too: The mantra of open source has been "release early and often", which means IT managers using a disparate group of open-source apps face frequent updates and patches, and must craft rules about how and when to apply them.

Most enterprises soon find that with the do-it-yourself approach, maintenance and integration costs equal - and sometimes exceed - the maintenance cost of commercial software, due to the in-house resources needed to track, test, and apply patches and updates. The other option, using professional services firms to do that work, costs at least as much.

But a new, potentially less expensive approach is emerging - a certified, preintegrated suite of open-source components from one vendor, which stays updated and integrated via periodic suite releases.

This option could make open-source adoption easier, for example, for smaller enterprises that don't have the staff or services dollars to support the traditional open-source integration and maintenance approaches but want to use proven open-source technologies like Linux, EnterpriseDB, Postfix, Tomcat and Apache more broadly.

"By creating a standard set of services, providers create cost savings and improved quality," says Julie Giera, a vice president at Forrester Research.

For instance, hardware-and-consulting vendor Unisys recently announced its Open and Secure Integrated Solutions (Oasis) suite - a group of open-source tools optimized for large enterprise customers, with a service-level agreement (SLA) that remains in effect as long as the customer doesn't modify the software. The established trio of automated open-source support vendors - OpenLogic, SourceLabs and SpikeSource - now offer preintegrated suites, or stacks, of open-source components in addition to their previous offerings (management tools that track and patch open-source software across an enterprise). And Red Hat sells a release of the JBoss application server with other middleware components integrated.

However, the preintegrated approach will not suit every IT department. Many CIOs lack enthusiasm for it, due to issues like vendor lock-in and lack of flexibility - and you should weigh these factors as you consider the fit for your organization.