Below are a few select projects that we have worked on. They mostly include work done for the SDL Tridion community and less commercial involvements, which are usually protected by Non Disclosure Agreements (NDAs).

Java Mediator
Yes, you can write SDL Tridion templates in Java. Whether they are Java code fragments, JSPs or JAR libraries, the Java Mediator makes it all possible.
Tridion templating in Java

OData Query Extension
This extension exposes the full CD search capabilities to OData. It includes custom metadata search, custom ordering and pagination.
Content Delivery Query

RSTL
REL Standard Tag Library completes the SDL Tridion's Rendering Expression Language (REL) with essential functionality such as loops, conditionals, XSLT.
REL Standard Tag Library

Core Service Java Client
A fully functional Java client that works with Tridion's Core Service. This elegant proxy API connects any Java client to the WCF web service.