A hunger for lighter-weight and lower-cost sales and CRM applications has brought great success to SaaS vendors such as Salesforce.com, and also lifted the fortunes of open source offerings in the space. Open source ERP has had a harder time breaking out, but here too there are several impressive offerings to choose from. And if you're looking to open source for an enterprise portal, CMS, or Microsoft Exchange substitute, you will not be disappointed.

Commercial open source pioneer SugarCRM is our top choice in CRM. Its trident of offerings -- installed, hosted, and a good drop-in appliance -- give IT the flexibility it needs, and the easy-to-use Ajax interface enhances user adoption. Users will also appreciate the offline client synchronization; integration with Microsoft Outlook and Microsoft Word is enterprise-grade.

The proficient Sugar app is becoming polished. The recently released 5.0 beta shows off advances in charting and performance dashboards, plus a new AJAX (Asynchronous JavaScript and XML) e-mail client and long-awaited field-level access controls. A new custom development kit makes it easier to develop new objects to meet vertical requirements.

Just as important, a good developer community has taken shape around SugarCRM, making a library of plug-ins and feature enhancements available for the suite -- including VoIP integration.

SugarCRM has no shortage of competition from open source rivals Centric CRM, CentraView, and openCRX. The most notable of these is Java-based Centric CRM, which touts team collaboration tools for customer service and salesforce automation, as well as strong online marketing tools forged through a relationship with open source demand generation software vendor LoopFuse. A recent influx of capital from Intel won't hurt it any, either. Long dominated by big guns such as SAP and Oracle/PeopleSoft, ERP has earned a reputation for complexity, and its proximity to the revenue pipeline discourages disruption. As a result, change happens slowly in the ERP market, making it difficult for the bright lights of open source ERP -- Apache OFBiz, Compiere, ERP5, Openbravo, OpenMFG/Postbooks, and TinyERP -- to shine through.

Further, none of these open source solutions yet compares with the breadth of back office functionality, usability, and integration found in today's SaaS offerings, such as NetSuite.

Nevertheless, from the hills of Pamplona, Spain, comes a viable if unlikely candidate for many small and midsize implementations: Openbravo. Openbravo does a fine job of managing general business duties like procurement and product pricing, warehouse and inventory management, production, and financial accounting. Its MRP (materials requirement planning) and sales/CRM modules are also good, and the capability to handle multi-phase projects and partner relationships help set it apart.

Openbravo comes up light on HR, customer-to-Web, and document management, but decent BI and balanced scorecard capability in addition to a solid Java development framework for building add-ons boost its enterprise credentials. The recent addition of the JasperReports engine lets users push out professional-looking PDF, Excel, and HTML reports.

Openbravo takes the Bossie, but also notable is Compiere. A split last year between members led to a forked faction founding the alternative ADempiere project, slowing the company momentum a bit. Nevertheless, Compiere's point-of-sale and CRM modules make it worth a look.

We're also a fan of the Apache Open for Business (OFBiz) project, but this formidable solution is not for the technically faint of heart. OFBiz is better suited to VARs than SMEs. Another worthy offering is xTuple's OpenMFG, a Windows-based manufacturing solution with good reporting. OpenMFG is not technically open source, as is its lighter-weight sibling PostBooks, but xTuple does provide code for in-house customization.