Workbench is a powerful, web-based suite of tools designed for administrators and developers to interact with Salesforce.com organizations via the Force.com APIs. Workbench includes robust support for the Force.com Partner, Bulk, Rest, Streaming, Metadata, and Apex APIs that allows users to describe, query, manipulate, and migrate both data and metadata in Salesforce.com organizations directly in their web browser with a simple and intuitive user interface. Workbench also provides many advanced features for testing and troubleshooting the Force.com APIs, such as customizable SOAP headers, debug logs for API traffic, backward compatibility testing with previous API versions, and single sign-on integration within the Salesforce application.
Workbench is publicly hosted at workbench.developerforce.com and is also available for download for private installation. Workbench can also be deployed to Heroku, which is great for spinning up a public instance during development in a fork.
For installation of Workbench, please see the installation section of the wiki.
If you running into problems, post a message on the Workbench discussion group. Please note that the Workbench is NOT a supported product of or supported by salesforce.com, inc.