TFS4JIRA plugin licensing model

TFS4JIRA plugin licensing rules are based on standard Atlassian Marketplace model. You can find extensive information on the topic on Atlassian Marketplace Purchasing FAQ page. In brief:

Evaluating TFS4JIRA plugin

You can test fully functional TFS4JIRA plugin for 30 days by obtaining an evaluation license. The easiest way to do it is to navigate to Jira Manage Add-ons (Manage plugins) administration page, locate the plugin in User-installed plugins section and click Free Trial button. You will then be redirected to site, where you can obtain an evaluation license.

Buying TFS4JIRA license

You can buy a license by clicking Buy Now button on Manage add-ons Jira screen (see screenshot above) or you may go to plugin's Marketplace page and start from there.