Almost daily, headlines proclaim how businesses are cutting costs and improving productivity by using Linux-based, open-source software. But open-source is more than just Linux: Plenty of free, open-source applications are available for Windows and Mac OS X, as well.

Everyone is familiar with the Mozilla Firefox Web browser, and the audience for the office suite continues to grow, but those programs are only the tip of the iceberg. Presented here are just a few of the powerful open-source alternatives to major commercial software that can help keep your small business humming on a shoestring budget--provided you can handle a few rough edges.

Plan projects for peanuts

A lot of open-source projects are themselves loosely managed affairs, so it's no surprise that project-planning software à la Microsoft Project isn't high on many open-source developers' priority lists. Open Workbench, however, provides many of the same features as the paid app does, and it's completely free.

It began life as the product of a commercial software company, Niku, but spun off as an open-source project when Computer Associates acquired Niku in 2005. Open Workbench's various features are similar to Microsoft Project's (although CA would argue that its operating philosophy is fundamentally different). Plus, owing to its commercial origins, Open Workbench's user interface is refreshingly polished for an open-source offering.

Where it falls short is in its upgrade path: Who knows if there even is one? The most recent version dates back to 2005, proof that its development community is virtually nonexistent. Worse, Open Workbench's collaboration features function only if you buy an expensive server product from CA. Regardless, for a single user, Open Workbench is mature project-management software that gets the job done.

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