The so-called community versions also serve as advertising. The companies want you to adopt them easily because a happy user is much more likely to upgrade to a professional version later. But they've also arranged things so that it's easy to outgrow the basic systems. Some may see this as a cynical ploy, but I've come to view these trial mechanisms as one of the gentlest and kindest forms of marketing around. It may not be as much fun as getting the sales rep to take you on a boondoggle to Las Vegas, but it's much better than sitting through PowerPoint slides filled with buzzwords and promises. Negotiating the decision between an open source or the professional version is full of nuances and choices, but everything is out in the open.

[ Jitterbit offers an easy GUI for data migration projects, but Talend Open Studio is tops for enterprise data integration. See the Test Center review, "Open source data aces." ]

For this piece, we concentrated on SugarCRM, Openbravo, and Compiere, although many similar tools might do the job. For instance, many e-commerce front ends offer so many features that they might be considered ERP platforms themselves. Companies like Magento are offering e-commerce solutions that provide nice storefronts with many back-office tools.

The stores tools are also appearing in unexpected places. Projects like Drupal and Joomla are supposed to be CMSes, but programmers are building shopping carts and other tools that are turning them into storefronts that offer enough features to be ERPs for small businesses.

Other acronyms are also growing into the ERP space. Business intelligence (BI), the newest buzzword for the reporting tools, is sophisticated enough to handle many of the ERP and CRM chores. Jasper and Pentaho are much more than just tools for dumping SQL queries into nice-looking tables. It doesn't take long to build your own CRM or ERP solutions from tools like this.

Business process management (BPM or BPMS), the art of turning flowcharts for how the employees interact into software that keeps everything running smoothly, might also be a good fit for some CRM or ERP instances. Intalio pulls together a BPM solution from open source parts.

But SugarCRM, Openbravo, and Compiere tackle the essential CRM and ERP functions head-on. Taking a close look at these three offerings gave us a chance to see how easy it is to build up a functioning back end and to understand just what the term "open source" means to someone with a boss who just wants the warehouse to talk with the sales force. All of the philosophical debates aren't as important when the database connection is being overwhelmed just before the Christmas rush.