Whether the community edition is the most cost-effective solution depends largely upon the nature of your business and the need for customization. If your customers and products map directly onto the simple table structure, then it's possible to do quite well with the community editions. After all, you can even build replacements for some of the commercial features that aren't included in the free edition. Simple reporting features, for instance, can be whipped together with JasperReports because it's always possible to tie into the database without going through the main application.

Doing all of the work yourself, though, may be much more trouble than it's worth. I've found that it often doesn't take much time to do the programming work itself, but it can take a long time understanding the architecture and deciding how to implement the changes. It takes time to build up the expertise. While $50 per seat per month adds up pretty quickly, it's much less expensive than hiring a full-time programmer for a big part of the year.

[ See the best that open source has to offer -- in collaboration, developer tools, enterprise applications, networking, platforms and middleware,productivity applications, security, and storage -- in InfoWorld's Bossies 2008. ]

The professional versions do include more support and -- in the case of Compiere -- access to the documentation. This is often pretty valuable, but it still requires you to do the actual customization work. None of the professional versions include this work -- that's your responsibility -- but the companies all support a network of programmers who are versed in the idiosyncrasies of each version. Even companies with a deep collection of programmers will want to consider hiring some help when installing these packages.

It's also important to take note of the amount of openness built into the products themselves. Customizing Openbravo, for instance, involves creating XML and Java classes. The results need to be compiled. SugarCRM now includes a very sophisticated drag-and-drop tool for adding tables and modules to your implementation. You can add fields and control how they appear without writing any ASCII text. All of the programming is done "visually" with AJAX-level dragging and editing of divs on the screen. It's a very nice level of openness that will be accessible to many managers and users without direct programming experience.

I should say that while SugarCRM's drag-and-drop tool makes it much easier to change tables and data models, it doesn't remove the need to think ahead about how the data will be used by everyone. It may be dangerous to let everyone add fields as they see fit because it can lead to a loss of coherence.