Apromore is an open and extensible repository to store and disclose business process models of a variety of types and languages, such as BPMN, eEPCs, BPEL, YAWL, Workflow nets. Beyond that, Apromore provides state-of-the-art features to facilitate the management of large process model collections.
Wikipedia, a free encyclopedia, has an entry about the original control-flow patterns.
A workflow course based on the workflow book of MIT Press
A website presenting the joint activities of TU/e and QUT in the BPM arena
A website on process mining
A website on process configuration
A website on topics related to workflow and business process management and including a forum

YAWL (Yet Another Workflow Language)
A workflow language/system based on the patterns

Service Interaction Patterns
A collection of patterns that can be used in service choreographies.

Patterns for Enterprise Application Integration
A collection of message-driven application integration patterns complementary to the workflow patterns and ebPML's page discussing the workflow patterns

Patterns home page
Source for information about all aspects of software patterns and pattern languages

Proceedings of BPM 2003 published by Springer as volume 2678 of Lecture Notes in Computer Science and the edited book Business Process Management published as volume 1806 in the same series. If you have sufficient access to the Springer site, you can find the full papers there

Java Specification Request: Process Definition for Java (JSR 207)

Information Systems at TUE

Architecture of Information Systems (AIS) Group

BPM group at QUT

Workflow in Java

See Vendors for links to systems