If the phrase "open source software" continues to conjure images of impassioned programmers selflessly collaborating for the common good, it may be because, even as commercial interests are behind many of the most prominent projects, the results are no less inspired -- and typically no less free. Yes, advanced functionality or maintenance and support may require writing a check, but freeloaders looking for high-quality software -- of almost any kind -- have never had it so good.

Chosen by InfoWorld Test Center editors, analysts, and reviewers, InfoWorld's annual Best of Open Source Software awards (or Bossies, for short) celebrate the best products that open source has to offer: the best free software on the planet for businesses, their IT staffs, and their employees' workstations.

Our 2008 winners include 60 products in eight categories: enterprise applications such as CRM, ERP, BI, and reporting; collaborative applications, including mail/calendar, wiki, and social networking; desktop productivity apps from office suites to 3-D modeling; platforms and middleware, including operating systems, databases, virtualization, and SOA integration; developer tools from AJAX and rich Internet apps to Web service testing and version control; networking, including server monitoring, routing, Wi-Fi scanning, and VoIP software; security software, including firewall, IDS, disk encryption, and security testing;  and storage, including monitoring and administration, backup, and NAS.

Some of our picks were easy. For office productivity suite, what else but OpenOffice.org? For network intrusion detection, what else but Snort? And for security log analysis, nothing beats Splunk. Even in areas where good options abound, sometimes one solution is head and shoulders above the rest: In CRM, Sugar; in content management, Alfresco; in IP telephony, Asterisk.

But in most categories, stiff competition made the choice difficult. Would it be JasperSoft or Pentaho for BI? Scalix or Zimbra for groupware? Compiere or Openbravo for ERP? How to select the best JavaScript framework from among the likes of Dojo, Google Web Toolkit, Prototype, Yahoo User Interface, and so many others? Choosing often wasn't easy, but we took a close look and made our call.

In almost every category we explored, the pace of development is remarkable and products are evolving fast. A few of our 2008 winners -- Sugar, Alfresco, Asterisk -- are repeat champions ( see Bossies 2007). But in many categories -- most notably ERP and SOA middleware -- 2007's winner fails to take the 2008 prize.

Our 60 winners, and the fact that so many categories are hotly contested, are a testament to the tremendous impact that free and open source software is having across the software landscape. Although we found almost twice as many product categories to award in 2008 as in 2007, we realize we have plenty more work to do. Let us know what we missed.