You need JIRA with the GreenHopper plugin, and Confluence. Summary of steps:

• Install and configure the GreenHopper plugin in JIRA. See the GreenHopper installation guide.
• Configure JIRA to trust Confluence. See the JIRA administrator's guide. Follow the prompts to choose either OAuth or Trusted Applications, depending on your setup.
• In Confluence, subscribe to all your JIRA gadgets. Alternatively, you can add just this one gadget to Confluence's list of authorised external gadgets. see the Confluence administrator's guide.
• Add the gadget to a wiki page via the macro browser. See the Confluence user's guide.