ezSQL is an open source PHP database class that I wrote a while back. It’s used on over 100k websites and is the backbone of many open source projects such as WordPress. The class makes it ridiculously easy to use mySQL, Oracle8, SQLite (PHP), within your PHP script.
Activiti is a light-weight workflow and Business Process Management (BPM) Platform targeted at business people, developers and system admins. Its core is a super-fast and rock-solid BPMN 2 process engine for Java. It's open-source and distributed under the Apache license. Activiti runs in any Java application, on a server, on a cluster or in the cloud. It integrates perfectly with Spring, it is extremely lightweight and based on simple concepts.
Esper and NEsper enable rapid development of applications that process large volumes of incoming messages or events. Esper and NEsper filter and analyze events in various ways, and respond to conditions of interest in real-time.