JIRA finally gets its own REST API
JIRA's got a real REST API now:
REST easy with JIRA 5 | Atlassian Blogs: Now that JIRA 5 is out, lets talk about one of my favorite features of this new release, JIRAs new REST API. JIRA has supported remote APIs for many years with SOAP, XML-RPC, and JSON-RPC. However, telling developers that you support SOAP (and only SOAP) is like saying that you like writing applications with COBOL its out of style. Todays cool kids gravitate towards REST. Its clean, simple, and highly portable across languages and frameworks.
And checkout the nice looking API docs, which look like they were generated by WADL-to-HTML.
An alternative to Atlassian's new API is the recently release Rational OSLC Adapter for JIRA, which allows you to do more sophisticated integrations with JIRA including delegated UIs for issue creation and selection.