Subversion is a version control system. Originally designed to be a compelling replacement for CVS in the open source community, it has far exceeded that goal and seen widespread adoption in both open source and corporate environments. The Subversion project produces Subversion's core libraries (written in C), a fully functional command line client (svn), repository administration programs, API bindings for various languages (Perl, Python, Java, Ruby, etc.), and various additional tools and scripts.
Apache SpamAssassin is an extensible email filter that is used to identify spam. Once identified, the mail can then be optionally tagged as spam for later filtering. It provides a command line tool to perform filtering, a client-server system to filter large volumes of mail, and Mail::SpamAssassin, a set of Perl modules allowing Apache SpamAssassin to be used in a wide variety of email systems.
KeyBox is a Web-based SSH console for executing commands and managing multiple systems simultaneously. It allows you to share terminal commands and upload files to all your systems. Once the sessions have been opened you can select a single system or any combination on which to run your commands. Also, additional system administrators can be added and their terminal sessions and history can be audited.
OrientDB is a NoSQL DBMS which can store 150,000 documents per second on common hardware. Even with a document-based database, the relationships are managed as in graph databases, with direct connections among records. You can traverse entire or parts of trees and graphs of records in a few milliseconds. It supports schema-less, schema-full, and schema-mixed modes, has a strong security profiling system based on users and roles, and supports SQL between the query languages. Thanks to the SQL layer, it's straightforward to use for people skilled in the relational world.
phpOpenTracker is a framework solution for the analysis of Web site traffic and visitor behaviour. It features a logging engine that, either invoked as a Web bug by an HTML image tag or embedded with two lines of code into your PHP application, logs each request to a Web site into a database. One installation can track an arbitrary number of Web sites. Through its API, you can easily access the gathered data and perform complex operations on it (for instance, the analysis of your visitors' click paths).
OWASP Zed Attack Proxy (ZAP) is an easy-to-use integrated penetration testing tool for finding vulnerabilities in Web applications. It is designed to be used by people with a wide range of security experience and as such is ideal for developers and functional testers who are new to penetration testing as well as being a useful addition to an experienced pen tester's toolbox. ZAP provides automated scanners as well as a set of tools that allow you to find security vulnerabilities manually.