The Fressia Project is an effort to develop a framework for testing automation. It's intended for users (testers) who want a simple tool that can be used just out of the box. It was originally conceived as part of the QA efforts at the US National Optical Astronomy Observatory. It has been delivered to the community because, despite it still being at early stages, it has proven to be a useful general purpose testing tool. It is designed to provide functional testing, system testing, system integration testing, white (black) box testing, automated regression testing, acceptance testing, etc.
Zadok is a multi-language test suite runner. It is designed to run small test programs written in one of the programming or scripting languages that it understands, compare their output to what is expected, and determine a pass or fail. Tests are grouped into suites for conceptual organization purposes.
Simple Fuzzer is a very simple fuzzer. It is reminiscent of easy-fuzz from 2004, written by priest of the priestmasters. His layout for building a fuzzy test was a "script" file with a preamble, setting some basic state and variables followed by the "meat and potatoes" tests. This approach was borrowed for Simple Fuzzer.
Citrus is a test framework written in Java that enables automated integration testing of message-based enterprise SOA applications. The tool can easily simulate surrounding systems across various transports and protocols (e.g. JMS, SOAP WebServices, HTTP, TCP/IP, etc.) in order to perform end-to-end use case testing. Citrus provides strong validation mechanisms for XML message contents and allows you to build complex testing logic such as sending and receiving messages, database validation, automatic retries, variable definitions, dynamic message contents, error simulation, and many more.
The Java Engine for Testing (JET) is a system for running distributed automated tests. It has been used by Sun for testing the High Availability DataBase (HADB), JavaDB, PostgreSQL, Memcached, and the MySQL Cluster Manager. JET should be a good way to write your tests if the product you want to test is distributed or has a client/server architecture, if it is natural for you to write the tests in Java, and if you want to invest time in developing tests and abstractions for later reuse.
6jack is a framework for testing, analyzing, and fuzzing network applications. 6jack runs a command, intercepts calls to common network-related system calls, and passes them through an external filter. A filter can be written in any language supporting the MessagePack serialization library. 6jack is especially useful for writing tests for clients and servers, debugging and reverse engineering protocols, sketching filtering proxies, and fuzzing.