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.
Jailer is a database subsetting and browsing tool. It is a tool for data exporting, schema browsing, and rendering. It exports consistent, referentially intact row-sets from relational databases. It removes obsolete data without violating integrity. It is DBMS agnostic (by using JDBC), platform independent, and generates DbUnit datasets, hierarchically structured XML, and topologically sorted SQL-DML.
The Apache Open For Business Project is an enterprise automation software project that includes ERP, CRM, E-Business/E-Commerce, SCM, MRP, and CMMS/EAM functions. It is a foundation and starting point for enterprise solutions and can certainly be used out of the box, but is also great for creating specialized applications.
With MetaModel, you use a type-safe SQL-like API for querying any datastore. It is a data access framework providing a common interface for exploration and querying of different types of datastores. It isn't a data mapping framework. Instead, it emphasizes abstraction of metadata and the ability to add data sources at runtime, making MetaModel great for generic data processing applications, but less so for applications modeled around a particular domain.
DataVision is a reporting tool similar to Crystal Reports. Reports can be designed using a drag-and-drop GUI or a text editor. They may be run, viewed, and printed from the application or exported as HTML, XML, PDF, Excel, LaTeX2e, DocBook, or tab- or comma-delimited text files. The output files produced by LaTeX2e and DocBook can in turn be used to produce PDF, text, HTML, PostScript, and more. It can generate reports from JDBC databases or text data files. Report descriptions are stored as XML files.