Logfilter is a tool for performing ad hoc analysis on Apache log files. Logfilter is especially useful when you wish to find records matching very specific criteria, since you can specify exactly which fields to match. The tool also plays well in a Unix environment by accepting input either through files or via stdin.
tools4j-config supports long-running enterprise Java applications with a framework for handling configuration changes without restarting. It also aids in developing applications which are decoupled from knowing how and where to store, retrieve, and validate configurations. The aim is to liberate applications to use configurations seamlessly on the terms of their particular environment, without constraining them to Java SE, EE, OSGi, Spring, CDI, or any other programming model or framework.
jRapidRPC is a Java RPC library that allows you to create client-server applications that talk in objects. It is small, fast, and extensible. Its smallness helps you learn how to use the library quickly. jRapidRPC is fast due to its compact size and lack of complexity. Also, it uses the ProtoStuff serializer by default. jRapidRPC's extensibility allows you to can write a new client-server or a new serializer.
Ammentos is a lightweight persistence framework for JDK 5. It does not require any installation nor configuration; just put a jar file into your classpath and start writing code. It is designed so that your persistence code will be dramatically short and so that you won't have to spend a lot of time to learn how to use it. It is about 72Kb large and it does not require any external library except for your database JDBC driver. You can use it in desktop applications or in server-based environments.