Free Java Reporting Library
Open Hospital - Hospital Information System
SmartPOS (Includes->SmartERP distro of Idempiere ERP) is 100% Web
An open source search engine with RESTFul API and crawlers
Open Source Enterprise Content Management ECM
Generating documents and reports, offline enabled and reliable.
jBilling is a web-based enterprise billing system.
An absolutely free customer relationship managment (CRM) application