This is a fork of the probably discontinued Atlassian IDE Connector for Eclipse which work on Eclipse 4.8. It has been tested with MacOS and Linux and as Java code it should work everywhere.
The connector has been lightly tested with JIRA 6.3.1 on-premise and Atlassian Cloud.
In an Eclipse Photon distribution with Mylyn installed or included (like JEE), install the archive provided in the current release :
Create a task repository from Mylyn dedicated view "Tasks repositories".
If you want to use Atlassian Cloud, create and use an API token as the password in the configuration of the task repository : API tokens
The release should work but the source is probably not ready to use, one have to add to the target Eclipse Platform the Mylyn bundles and the bundles folder in order to export the JIRA connector feature from Eclipse.